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diff --git a/docs/source/lang/cpp/arithmetic.rst b/docs/source/lang/cpp/arithmetic.rst deleted file mode 100644 index cef3954..0000000 --- a/docs/source/lang/cpp/arithmetic.rst +++ /dev/null @@ -1,124 +0,0 @@ -.. highlight:: cpp - -.. _lang-arithmetic: - -Arithmetic Operators (``+``, ``-``, ``*``, ``/``) -================================================= - -The operators ``+``, ``-``, ``*``, and ``/`` respectively evaluate to -the sum, difference, product, or quotient (respectively) of the two -operands. The operation is conducted using the data type of the -operands, so, for example, ``9 / 4`` gives ``2`` since 9 and 4 are -:ref:`int variables <lang-int>`. - -This also means that the operation can overflow if the result is -larger than that which can be stored in the data type (e.g. adding 1 -to an :ref:`lang-int` with the value 2,147,483,647 gives --2,147,483,648). - -.. _lang-arithmetic-typeconversion: - -If the operands are of different types, the "larger" type is used for -the calculation. If one of the numbers (operands) are of the type -**float** or of type **double**, floating point math will be used for -the calculation. - -.. note:: The specifics of these rules are beyond the scope of this - documentation; for more information, see `The C++ Programming - Language <http://www2.research.att.com/~bs/3rd.html>`_\ , by Bjarne - Stroustroup, Appendix C, especially §§C.4-C.6, or `this WikiBooks - entry on C++ type conversion - <http://en.wikibooks.org/wiki/C%2B%2B_Programming/Programming_Languages/C%2B%2B/Code/Statements/Variables/Type_Casting#Automatic_type_conversion>`_. - -.. note:: For more information on how computers represent integers, - see the Wikipedia page on `two's complement - <http://en.wikipedia.org/wiki/Two's_complement>`_. - -.. contents:: Contents - :local: - -Examples --------- - - :: - - y = y + 3; - x = x - 7; - i = j * 6; - r = r / 5; - - -Syntax ------- - - :: - - result = value1 + value2; - result = value1 - value2; - result = value1 * value2; - result = value1 / value2; - - -Parameters ----------- - -**value1**: any numeric variable or constant - -**value2**: any numeric variable or constant - -Programming Tips ----------------- - -- Know that :ref:`integer constants <lang-constants-integers>` - default to :ref:`int <lang-int>`, so some constant calculations - may overflow (e.g., 200000 * 5000000 will yield a negative result). - -- Choose variable sizes that are large enough to hold the largest - results from your calculations. - -- Know at what point your variable will "roll over" and also what - happens in the other direction e.g. (0 - 1) for unsigned arithmetic, - or (0 - -2,147,483,648) for signed arithmetic. - -- For math that requires fractions, float variables may be used, but - be aware of their drawbacks: large size and slow computation speeds - (the STM32 has no floating point hardware, so all floating point - calculations have to be done in software). - -- Use cast operator, e.g. ``(int)myFloat`` to convert one variable type - to another on the fly. - -Arduino Compatibility ---------------------- - -Since the STM32 processor on the Maple is a 32-bit machine, the int -type overflows at a much higher value on Maple than on Arduino. In -particular, on Maple, ints do not overflow (become negative) until -they reach 2,147,483,648; on the Arduino, they overflow at 32,767. -Because of this, programs running on Maple are much less likely to run -into overflow issues. The following table summarizes the sizes and -ranges of integer datatypes on the Maple (the ranges of ``long long`` -types are approximate): - -.. _lang-arithmetic-int-sizes: - -.. csv-table:: - :header: Datatype, Unsigned range, Signed range, Size (bytes) - :widths: 8, 12, 17, 8 - - ``char``, 0 --- 255, -128 --- 127, 1 - ``short``, "0 --- 65,535", "-32,768 --- 32,767", 2 - ``int``, "0 --- 4,294,967,295", "-2,147,483,648 --- 2,147,483,647", 4 - ``long``, "0 --- 4,294,967,295", "-2,147,483,648 --- 2,147,483,647", 4 - ``long long``, "0 --- 1.8*10\ :sup:`19`\ " (approx.), "-9.2*10\ :sup:`18` --- 9.2*10\ :sup:`18` (approx.)", 8 - - -See Also --------- - -- The individual sizes (in bits) of various available types are - defined in :ref:`libmaple_types.h <libmaple-libmaple_types>`. - -- :ref:`sizeof <lang-sizeof>`\ () - -.. include:: /arduino-cc-attribution.txt diff --git a/docs/source/lang/cpp/array.rst b/docs/source/lang/cpp/array.rst deleted file mode 100644 index 39d4d91..0000000 --- a/docs/source/lang/cpp/array.rst +++ /dev/null @@ -1,121 +0,0 @@ -.. highlight:: cpp - -.. _lang-array: - -Arrays -====== - -An array is a collection of variables that are accessed with an index -number. Arrays in the C++ programming language, in which the Maple is -programmed, can be complicated, but using simple arrays is relatively -straightforward. - -.. contents:: Contents - :local: - -Creating (Declaring) an Array ------------------------------ - -All of the methods below are valid ways to create (declare) an -array. :: - - int myInts[6]; - int myPins[] = {2, 4, 8, 3, 6}; - int mySensVals[6] = {2, 4, -8, 3, 2}; - char message[6] = "hello"; - -You can declare an array without initializing it, as with myInts. In -the line referring to myPins, we declare an array without explicitly -choosing a size. The compiler counts the elements and creates an -array of the appropriate size. - -Finally, you can both initialize and size your array, as in -mySensVals. Note that when declaring an array with elements of type -char, one more element than your initialization is required, to hold -the required `null character <http://en.wikipedia.org/wiki/Null-terminated_string>`_. - - -Accessing an Array ------------------- - - -.. compound:: - - Arrays are **zero indexed**; that is, referring to the array - initialization above, the first element of the array is at index 0, - hence :: - - mySensVals[0] == 2; - mySensVals[1] == 4 - - and so forth. - -It also means that in an array with ten elements, index nine is the -last element. Hence:: - - int myArray[10]={9,3,2,4,3,2,7,8,9,11}; - // myArray[9] contains 11 - // myArray[10] is invalid and contains random information (other memory address) - -For this reason, you should be careful in accessing arrays. Accessing -past the end of an array (using an index number greater than your -declared array size - 1) is reading from memory that is in use for -other purposes. Reading from these locations is probably not going to -do much except yield invalid data. Writing to random memory locations -is definitely a bad idea, and can often lead to unhappy results such -as crashes or program malfunction. This can also be a difficult bug to -track down. - -Unlike Basic or Java, the C compiler does no checking to see if array -access is within legal bounds of the array size that you have -declared. - - -To assign a value to an array ------------------------------ - :: - - mySensVals[0] = 10; - - -To retrieve a value from an array ---------------------------------- - - :: - - x = mySensVals[4]; - - -Arrays and ``for`` Loops ------------------------- - -Arrays are often manipulated inside :ref:`for loops <lang-for>`, where -the loop counter is used as the index for each array element. For -example, to print the elements of an array over the serial port, you -could do something like this:: - - int i; - for (i = 0; i < 5; i = i + 1) { - SerialUSB.println(myPins[i]); - } - - -Example -------- - -For a complete program that demonstrates the use of arrays, see the -Arduino `Knight Rider example -<http://www.arduino.cc/en/Tutorial/KnightRider>`_\ (which will run -unmodified on the Maple). - -Arduino Compatibility ---------------------- - -Arrays on Maple are identical those on Arduino. - -See Also --------- - -- :ref:`Storing arrays in FLASH memory <arm-gcc-attribute-flash>` - -.. include:: /arduino-cc-attribution.txt diff --git a/docs/source/lang/cpp/assignment.rst b/docs/source/lang/cpp/assignment.rst deleted file mode 100644 index 6379298..0000000 --- a/docs/source/lang/cpp/assignment.rst +++ /dev/null @@ -1,60 +0,0 @@ -.. highlight:: cpp - -.. _lang-assignment: - -Assignment Operator (``=``) -=========================== - -Stores the value to the right of the equal sign in the variable to -the left of the equal sign. - -The single equal sign in the C++ programming language is called the -assignment operator. It has a different meaning than in algebra -class, where it indicated an equation or equality. The assignment -operator tells the microcontroller to evaluate whatever value or -expression is on the right side of the equal sign, and store it in -the variable to the left of the equal sign [#fgross]_. - -Example -------- - -:: - - int sensVal; // declare an integer variable named sensVal - sensVal = analogRead(0); // store the (digitized) input voltage at analog pin 0 in sensVal - -Programming Tips ----------------- - -The variable on the left side of the assignment operator (``=`` sign) -needs to be able to hold the value stored in it. If it is not large -enough to hold a value, the value stored in the variable will be -incorrect. - -Don't confuse the assignment operator ``=`` (single equal sign) with -the comparison operator ``==`` (double equal signs), which evaluates -whether two expressions are equal. - -Arduino Compatibility ---------------------- - -Assignments on the Maple are identical to those on Arduino. - -See Also --------- - -- :ref:`if <lang-if>` -- :ref:`char <lang-char>` -- :ref:`int <lang-int>` -- :ref:`long long <lang-longlong>` - -.. rubric:: Footnotes - -.. [#fgross] Experienced C++ programmers know this to be an - oversimplification of what happens when the variable on the left - hand side is an object. See Richard Gillam's wonderful and scary - `The Anatomy of the Assignment Operator - <http://icu-project.org/docs/papers/cpp_report/the_anatomy_of_the_assignment_operator.html>`_ - for more information. - -.. include:: /arduino-cc-attribution.txt diff --git a/docs/source/lang/cpp/bitshift.rst b/docs/source/lang/cpp/bitshift.rst deleted file mode 100644 index 47413f2..0000000 --- a/docs/source/lang/cpp/bitshift.rst +++ /dev/null @@ -1,143 +0,0 @@ -.. highlight:: cpp - -.. _lang-bitshift: - -Bit Shift Operators (``<<``, ``>>``) -==================================== - -(Adapted from `The Bit Math Tutorial -<http://www.arduino.cc/playground/Code/BitMath>`_ in `The Arduino -Playground <http://www.arduino.cc/playground/Main/HomePage>`_\ ) - -There are two bit shift operators in C++: the left shift operator -``<<`` and the right shift operator ``>>``. These operators cause the -bits in the left operand to be shifted left or right by the number of -positions specified by the right operand. - -More information on bitwise math can be obtained in the Wikipedia -article on `bitwise operations -<http://en.wikipedia.org/wiki/Bitwise_operation>`_\ , especially the -section on shifts in `C, C++, and Java -<http://en.wikipedia.org/wiki/Bitwise_operation#Shifts_in_C.2C_C.2B.2B.2C_C.23_and_Java>`_\ . - - -Syntax ------- - -``some_int << number_of_bits`` - -``some_int >> number_of_bits`` - - -Parameters ----------- - -* **some_int** An integer value or variable. - -* **number_of_bits** integer whose value is at most ``8 * - sizeof(variable)`` (so ``number_of_bits`` can be at most 32 for - ``int`` values, at most ``8`` for ``char`` values, etc.; the various - integer sizes are summarized :ref:`in this table - <lang-arithmetic-int-sizes>`\ ). - - - -Example: --------- - -Here are some examples of bit shifting, with the binary representation of the number in comments:: - - int a = 5; // binary: 101 - int b = a << 3; // binary: 101000, or 40 in decimal - int c = b >> 3; // binary: 101, or back to 5 like we started with - - -When you left shift a value x by y bits (x << y), the leftmost y bits -in x are lost, literally shifted out of existence. We'll do this -example with ``char`` values (which are integers in the range 0-255, -and take up 8 bits of memory):: - - char a = 5; // binary (all 8 bits): 00000101 - char b = a << 7; // binary: 10000000 - the first 1 in 101 was discarded - - -If you are certain that none of the ones in a value are being shifted -into oblivion, a simple way to think of the left-shift operator is -that it multiplies the left operand by 2 raised to the right operand -power (in math notation, ``x << y`` equals x * 2\ :sup:`y`\ , as long -as none of the bits of x get shifted out). For example, to generate -powers of 2, the following expressions can be employed:: - - 1 << 0 == 1 - 1 << 1 == 2 - 1 << 2 == 4 - 1 << 3 == 8 - ... - 1 << 8 == 256 - 1 << 9 == 512 - 1 << 10 == 1024 - ... - -.. _lang-bitshift-signbit-gotcha: - -When you shift x right by y bits (``x >> y``), and the highest bit in -x is a 1, the behavior depends on the exact data type of x. If x is of -type ``int``, the highest bit is special, and determines whether x is -negative or not; the details are too complicated to explain here, but -they are thoroughly explained in the Wikipedia article on `two's -complement arithmetic -<http://en.wikipedia.org/wiki/Two%27s_complement>`_\ , which the -system most computers use to store integers. In that case, the sign -bit is copied into lower bits, for esoteric historical reasons:: - - int x = -16; // binary (all 32 bits): 11111111111111111111111111110000 - int y = x >> 3; // binary: 11111111111111111111111111111110 - - - -This behavior, called "sign extension", is often not what you -want. You probably wish zeros to be shifted in from the left. It -turns out that the right shift rules are different for ``unsigned -int`` values, so you can use a type cast to suppress ones being copied -from the left:: - - int x = -16; // binary: 11111111111111111111111111110000 - int y = (unsigned int)x >> 3; // binary: 00011111111111111111111111111110 - - - -If you are careful to avoid sign extension, you can use the -right-shift operator, ``>>``, as a way to divide by powers of 2. For -example:: - - int x = 1000; - int y = x >> 3; // integer division of 1000 by 8, causing y = 125. - - -Arduino Compatibility ---------------------- - -Since it's part of the C++ language, bit shifting on the Maple is -compatible with the Arduino; however, you should keep in mind that the -Maple has bigger integer types (as in, more bits) than the Arduino. - -Since the STM32 is a 32-bit processor, the ``int`` type takes up 32 -bits instead of 16, like on Arduino's 16-bit microcontroller. This -means that you can shift left, like ``x << y``, with bigger values of -``y`` on the Maple before ones in ``x`` start to get shifted out. - -To calculate the number of bits of an integer type on the Maple, -multiply its size in bytes (see :ref:`this table -<lang-arithmetic-int-sizes>` for these) by 8, since there are 8 -bits in 1 byte. For example, a ``short`` takes up 2 bytes of memory, -or 2 * 8 = 16 bits. - -See Also --------- - -- :ref:`lang-bit` -- :ref:`lang-bitread` -- :ref:`lang-bitwrite` -- :ref:`lang-bitclear` - -.. include:: /arduino-cc-attribution.txt diff --git a/docs/source/lang/cpp/bitwisemath.rst b/docs/source/lang/cpp/bitwisemath.rst deleted file mode 100644 index cfe34f2..0000000 --- a/docs/source/lang/cpp/bitwisemath.rst +++ /dev/null @@ -1,185 +0,0 @@ -.. highlight:: cpp - -.. _lang-bitwisemath: - -Bitwise Operators (``&``, ``|``, ``^``, ``~``) -============================================== - -The bitwise operators perform their calculations at the bit level of -variables. They help solve a wide range of common programming -problems. - -Much of the material here is adapted for Maple from an (Arduino) -`tutorial on bitwise math -<http://www.arduino.cc/playground/Code/BitMath>`_\ . Another great -resource is the Wikipedia article on `bitwise operations -<http://en.wikipedia.org/wiki/Bitwise_operation>`_\ . - -Below are descriptions and syntax for all of the operators. - -.. contents:: Contents - :local: - -.. _lang-bitwisemath-and: - -Bitwise AND (``&``) -------------------- - -The bitwise AND operator in C++ is a single ampersand, ``&``, used -between two other integer expressions. Bitwise AND operates on each -bit position of the surrounding expressions independently, according -to this rule: if both input bits are 1, the resulting output is 1, -otherwise the output is 0. Another way of expressing this is:: - - 0 0 1 1 operand1 - 0 1 0 1 operand2 - ---------- - 0 0 0 1 (operand1 & operand2) = result - - -On the Maple, the type ``int`` is a 32-bit value, so using ``&`` -between two ``int`` expressions causes 32 simultaneous AND operations -to occur. In a code fragment like:: - - int a = 92; // in binary: 00000000000000000000000001011100 - int b = 101; // in binary: 00000000000000000000000001100101 - int c = a & b; // result: 00000000000000000000000001000100, - // (or 68 in decimal). - - -Each of the 32 bits in ``a`` and ``b`` are processed using bitwise -AND, and all 32 resulting bits are stored in ``c``, resulting in the -value 1000100 in binary, which is 68 in decimal. - - -.. _lang-bitwisemath-or: - -Bitwise OR (``|``) ------------------- - -The bitwise OR operator in C++ is the vertical bar symbol, ``|``. Like -the ``&`` operator, ``|`` operates independently on each bit in its -two surrounding integer expressions, but what it does is -different. The bitwise OR of two bits is 1 if either or both of the -input bits is 1, otherwise it is 0. For example:: - - 0 0 1 1 operand1 - 0 1 0 1 operand2 - ---------- - 0 1 1 1 (operand1 | operand2) = result - -Here is an example of bitwise OR used in a snippet of C++ code (using -``char``, which takes up 8 bits of memory, instead of ``int``, which -uses 32):: - - char a = 92; // in binary: 01011100 - char b = 101; // in binary: 01100101 - char c = a | b; // result: 01111101, or 125 in decimal. - -.. _lang-bitwisemath-xor: - -Bitwise XOR (``^``) -------------------- - -There is a somewhat unusual operator in C++ called bitwise EXCLUSIVE -OR, also known as bitwise XOR. (In English, this is usually pronounced -"zor" or "ex-or"). The bitwise XOR operator is written using the caret -symbol, ``^``. This operator is very similar to the bitwise OR -operator ``|``, except it evaluates to 0 for a given bit position when -both of the input bits for that position are 1:: - - 0 0 1 1 operand1 - 0 1 0 1 operand2 - ---------- - 0 1 1 0 (operand1 ^ operand2) = result - - -Another way to look at bitwise XOR is that each bit in the result -is a 1 if the input bits are different, or 0 if they are the same. - -Here is a simple example:: - - int x = 12; // binary (ignoring extra bits): 1100 - int y = 10; // binary: 1010 - int z = x ^ y; // binary: 0110, or decimal 6 - - - -The ^ operator is often used to toggle (i.e. change from 0 to 1, or 1 -to 0) some of the bits in an integer expression. In a bitwise OR -operation if there is a 1 in the mask bit, that bit is inverted; if -there is a 0, the bit is not inverted and stays the same. Below is a -program to toggle the built-in LED pin (you can also accomplish this -with :ref:`lang-toggleled`):: - - // Toggle built-in LED pin - - int toggle = 0; - - // demo for Exclusive OR - void setup(){ - pinMode(BOARD_LED_PIN, OUTPUT); - } - - void loop(){ - toggle = toggle ^ 1; - digitalWrite(BOARD_LED_PIN, toggle); - delay(100); - } - -.. _lang-bitwisemath-not: - -Bitwise NOT (``~``) -------------------- - -The bitwise NOT operator in C++ is the tilde character ``~``. Unlike -``&`` and ``|``, the bitwise NOT operator is applied to a single -operand to its right. Bitwise NOT changes each bit to its opposite: 0 -becomes 1, and 1 becomes 0. For example:: - - 0 1 operand1 - ---- - 1 0 ~operand1 = result - -Another example:: - - char a = 103; // binary: 01100111 - char b = ~a; // binary: 10011000 = -104 - -You might be surprised to see a negative number like -104 as the -result of this operation. This is because the highest bit in an int -variable is the so-called "sign bit". If the highest bit is 1, the -number is interpreted as negative. This encoding of positive and -negative numbers is referred to as *two's complement*. For more -information, see the Wikipedia article on `two's -complement. <http://en.wikipedia.org/wiki/Twos_complement>`_ - -As an aside, it is interesting to note that (under two's complement -arithmetic) for any integer ``x``, ``~x`` is the same as ``-x-1``. - -At times, the sign bit in a signed integer expression can cause -some unwanted surprises. - - -Uses ----- - -One of the most common uses of bitwise operations is to select or -manipulate a particular bit (or bits) from an integer value, often -called `bit masking -<http://en.wikipedia.org/wiki/Mask_%28computing%29>`_\ . See the -linked Wikipedia article for more information and examples. - -If you really want to see bit-twiddling techniques in their full -glory, you could do much worse than to get yourself a copy of -`Hacker's Delight <http://www.hackersdelight.org/>`_\ . - - -See Also --------- - -- :ref:`Boolean operations <lang-boolean>` (``&&``, ``||``) -- :ref:`Compound bitwise operations <lang-compoundbitwise>` (``&=``, - ``|=``, ``^=``). - -.. include:: /arduino-cc-attribution.txt diff --git a/docs/source/lang/cpp/boolean.rst b/docs/source/lang/cpp/boolean.rst deleted file mode 100644 index f09345e..0000000 --- a/docs/source/lang/cpp/boolean.rst +++ /dev/null @@ -1,90 +0,0 @@ -.. highlight:: cpp - -.. _lang-boolean: - -Boolean Operators -================= - -These can be used inside the condition of an :ref:`if <lang-if>` -statement. Evaluate to :ref:`true <lang-constants-true>` or -:ref:`false <lang-constants-false>`. - -.. contents:: Contents - :local: - -.. _lang-boolean-and: - -&& (logical and) ----------------- - -True only if both operands are true. For example:: - - if (digitalRead(2) == HIGH && digitalRead(3) == HIGH) { // read two switches - // ... - } - -is true only if both inputs are high. Another example:: - - if (a >= 10 && a <= 20){} // true if a is between 10 and 20 - -**Be careful** not to say ``10 <= a <= 20``! This won't work the way -you want. You have to separately test whether ``a`` is at least 10 -using ``a >= 10``, then test whether ``a`` is at most 20 using ``a <= -20``, then combine the results using ``&&``. - - -.. _lang-boolean-or: - -\|\| (logical or) ------------------ - -True if either operand is true. For example:: - - if (x > 0 || y > 0) { - // ... - } - -is true if either ``x`` or ``y`` is greater than 0. - -.. _lang-boolean-not: - -! (logical not) ---------------- - -True if the operand is false. For example:: - - if (!x) { - // ... - } - -is true if ``x`` is false (i.e. if ``x`` is zero). - -Some Advice ------------ - -.. warning:: - - Make sure you don't mistake the boolean AND operator ``&&`` - (double ampersand) for the :ref:`bitwise AND operator - <lang-bitwisemath-and>` ``&`` (single ampersand). They are - entirely different beasts. - - Similarly, do not confuse the boolean OR operator ``||`` (double - pipe) with the :ref:`bitwise OR operator <lang-bitwisemath-or>` - ``|`` (single pipe). - - The :ref:`bitwise NOT operator <lang-bitwisemath-not>` ``~`` - (tilde) looks much different than the boolean not operator ``!`` - (exclamation point, or "bang", as some programmers say), but you - still have to be sure which one you want. - - -See Also --------- - -- :ref:`Bitwise operators <lang-bitwisemath>` (``&``, ``|``, ``^``, ``~``) -- :ref:`Compound bitwise operators <lang-compoundbitwise>` (``&=``, - ``|=``, ``^=``). -- :ref:`if statement <lang-if>` - -.. include:: /arduino-cc-attribution.txt diff --git a/docs/source/lang/cpp/booleanvariables.rst b/docs/source/lang/cpp/booleanvariables.rst deleted file mode 100644 index e032c74..0000000 --- a/docs/source/lang/cpp/booleanvariables.rst +++ /dev/null @@ -1,47 +0,0 @@ -.. highlight:: cpp - -.. _lang-booleanvariables: - -Booleans -======== - -A **boolean** holds one of two values, :ref:`true -<lang-constants-true>` or :ref:`false <lang-constants-false>`. On a -Maple, each boolean variable has type ``bool``. - -.. warning:: - - On an Arduino, the type ``boolean`` is also provided. While the - Maple also has this type for compatibility, **its use is strongly - discouraged**. The ``bool`` type is a standard part of C++, while - ``boolean`` is a non-standard extension that serves no purpose. - -Example -------- - -:: - - // running is a boolean variable: - bool running = false; - - void setup() { - pinMode(BOARD_LED_PIN, OUTPUT); - pinMode(BOARD_BUTTON_PIN, INPUT); - } - - void loop() { - if (isButtonPressed()) { - // button is pressed - running = !running; // toggle running variable - digitalWrite(BOARD_LED_PIN, running) // indicate via LED - } - } - -See Also --------- - -- :ref:`Boolean constants <lang-constants-bool>` -- :ref:`Boolean operators <lang-boolean>` -- :ref:`Variables <lang-variables>` - -.. include:: /arduino-cc-attribution.txt diff --git a/docs/source/lang/cpp/break.rst b/docs/source/lang/cpp/break.rst deleted file mode 100644 index f367b99..0000000 --- a/docs/source/lang/cpp/break.rst +++ /dev/null @@ -1,32 +0,0 @@ -.. highlight:: cpp - -.. _lang-break: - -``break`` -========= - -``break`` is used to exit from a :ref:`while <lang-while>`\ , -:ref:`for <lang-for>`\ , or :ref:`do/while <lang-dowhile>` loop, -bypassing the normal loop condition. It is also used to exit from a -:ref:`switch <lang-switchcase>` statement. - - -Example -------- - -:: - - for (x = 0; x < 255; x ++) - { - digitalWrite(PWMpin, x); - sens = analogRead(sensorPin); - if (sens > threshold){ // bail out on sensor detect - x = 0; - // this line of code means that we'll immediately exit - // from the "for" loop: - break; - } - delay(50); - } - -.. include:: /arduino-cc-attribution.txt diff --git a/docs/source/lang/cpp/built-in-types.rst b/docs/source/lang/cpp/built-in-types.rst deleted file mode 100644 index 28e8cdc..0000000 --- a/docs/source/lang/cpp/built-in-types.rst +++ /dev/null @@ -1,100 +0,0 @@ -.. highlight:: cpp - -.. _lang-built-in-types: - -================ - Built-in Types -================ - -This document serves as a reference for many of the built-in types -which are available when programming in the IDE. Programmers using -the :ref:`command-line tools <unix-toolchain>` will have access to -these types as long as they have imported `wirish.h -<https://github.com/leaflabs/libmaple/blob/master/wirish/wirish.h>`_; -several are defined in in `libmaple_types.h -<https://github.com/leaflabs/libmaple/blob/master/libmaple/libmaple_types.h>`_. - -.. _lang-built-in-types-integral: - -Integral types --------------- - -.. cpp:type:: char - - 8-bit integer value. - -.. cpp:type:: short - - 16-bit integer value. - -.. cpp:type:: int - - 32-bit integer value. - -.. cpp:type:: long - - 32-bit integer value. - -.. cpp:type:: long long - - 64-bit integer value. - -.. cpp:type:: int8 - - 8-bit integer value. Synonym for ``signed char``. - -.. cpp:type:: uint8 - - 8-bit unsigned integer value. Synonym for ``unsigned char``. - -.. cpp:type:: byte - - 8-bit unsigned integer value. Synonym for ``unsigned char``. - -.. cpp:type:: int16 - - 16-bit integer value. Synonym for ``short``. - -.. cpp:type:: uint16 - - 16-bit unsigned integer value. Synonym for ``unsigned short``. - -.. cpp:type:: int32 - - 32-bit integer value. Synonym for ``int``. - -.. cpp:type:: uint32 - - Unsigned 32-bit integer value. Synonym for ``unsigned int`` - -.. cpp:type:: int64 - - 64-bit integer value. Synonym for ``long long`` - -.. cpp:type:: uint64 - - Unsigned 64-bit integer value. Synonym for ``unsigned long long``. - -Floating-Point Types --------------------- - -.. cpp:type:: float - - 32-bit, IEEE-754 single-precision floating-point type. - -.. cpp:type:: double - - 64-bit, IEEE-754 double-precision floating-point type. - -Other Types ------------ - -.. cpp:type:: voidFuncPtr - - Pointer to a function that takes no arguments and returns nothing, i.e. :: - - typedef void (*voidFuncPtr)(void); - -.. cpp:type:: bool - - Boolean type. diff --git a/docs/source/lang/cpp/byte.rst b/docs/source/lang/cpp/byte.rst deleted file mode 100644 index 4634594..0000000 --- a/docs/source/lang/cpp/byte.rst +++ /dev/null @@ -1,33 +0,0 @@ -.. highlight:: cpp - -.. _lang-byte: - -byte -==== - -The ``byte`` type stores a 1-byte (8-bit) unsigned integer number, -from 0 to 255. - -.. warning:: - - The ``byte`` type is provided for compatibility with Arduino. - However, it is a non-standard extension. The standard C++ type for - storing an 8-bit unsigned integer is ``unsigned char``; we - recommend using that instead. (Your code will still work on an - Arduino). - - -Example -------- - -:: - - byte b = 134; - -See Also --------- - -- :ref:`byte() <lang-bytecast>` (casting a value to a byte) -- :ref:`Variables <lang-variables>` - -.. include:: /arduino-cc-attribution.txt diff --git a/docs/source/lang/cpp/bytecast.rst b/docs/source/lang/cpp/bytecast.rst deleted file mode 100644 index 24c3b9e..0000000 --- a/docs/source/lang/cpp/bytecast.rst +++ /dev/null @@ -1,44 +0,0 @@ -.. highlight:: cpp - -.. _lang-bytecast: - -byte() (cast) -============= - -Converts a value to the :ref:`byte <lang-byte>` data type. - -.. note:: - - Casting to the byte type is provided for compatibility with - Arduino. However, the recommended Maple type for storing an 8-bit - unsigned integer is ``uint8``. (C and C++ programmers: ``stdint.h`` - is also available). - - In order to cast a variable ``x`` to a ``uint8``, the - following syntax can be used:: - - uint8(x); - -Syntax ------- - -``byte(x)`` - -Parameters ----------- - -**x**: a value of any integer type - -Returns -------- - -The value, converted to a ``byte``. Note, however, that if the value -is larger than the maximum value you can store in a byte (255), then -the results might be strange and unexpected. - -See Also --------- - -- :ref:`lang-byte` - -.. include:: /arduino-cc-attribution.txt diff --git a/docs/source/lang/cpp/cc-attribution.txt b/docs/source/lang/cpp/cc-attribution.txt deleted file mode 100644 index e100140..0000000 --- a/docs/source/lang/cpp/cc-attribution.txt +++ /dev/null @@ -1,9 +0,0 @@ -.. Included in all this directory's files in order to satisfy the -.. Arduino CC Attribution-ShareAlike 3.0 License - -.. admonition:: License and Attribution - - This documentation page was adapted from the `Arduino Reference - Documentation <http://arduino.cc/en/Reference/HomePage>`_\ , which - is released under a `Creative Commons Attribution-ShareAlike 3.0 - License <http://creativecommons.org/licenses/by-sa/3.0/>`_. diff --git a/docs/source/lang/cpp/char.rst b/docs/source/lang/cpp/char.rst deleted file mode 100644 index 686c0d1..0000000 --- a/docs/source/lang/cpp/char.rst +++ /dev/null @@ -1,44 +0,0 @@ -.. highlight:: cpp - -.. _lang-char: - -``char`` -======== - -The ``char`` type stores a 1-byte character value (or integer with -value from -128 to 127). Character literals are written in single -quotes, like this: ``'A'`` (for multiple characters - strings - use -double quotes: ``"ABC"``). - -Just like everything else on a computer, characters are stored as -numbers. You can see the specific encoding in the `ASCII chart -<http://en.wikipedia.org/wiki/ASCII#ASCII_printable_characters>`_\ -. This means that it is possible to do arithmetic on characters, in -which the ASCII value of the character is used (e.g. ``'A' + 1`` has the -decimal value 66, since the ASCII value of the capital letter A in -decimal is 65). See the :ref:`Serial.println() -<lang-serial-println>` documentation for more information about how -characters are converted into numbers. - -The ``char`` datatype is a signed type, meaning that it encodes -numbers from -128 to 127. For an unsigned type, which stores values -from 0 to 255, just use the type ``unsigned char`` (two words). - -Example -------- - -:: - - // The following two lines are equivalent, using the ASCII - // character encoding: - char c = 'A'; - char c = 65; - -See Also --------- - -- :ref:`lang-int` -- :ref:`lang-array` (a string is just an array of ``char``\ s) -- :ref:`Serial.println() <lang-serial-println>` - -.. include:: cc-attribution.txt diff --git a/docs/source/lang/cpp/charcast.rst b/docs/source/lang/cpp/charcast.rst deleted file mode 100644 index 640ad85..0000000 --- a/docs/source/lang/cpp/charcast.rst +++ /dev/null @@ -1,32 +0,0 @@ -.. highlight:: cpp - -.. _lang-charcast: - -``char()`` (cast) -================= - -Converts a value to the :ref:`char <lang-char>` data type. - -Syntax ------- - -``char(x)`` - -Parameters ----------- - -**x**: a value of any type - -Returns -------- - -The value, converted to a ``char``. Note, however, that if the value -is outside the range of a ``char`` (-128 to 127), then the results -might be strange and unexpected. - -See Also --------- - -- :ref:`char <lang-char>` - -.. include:: /arduino-cc-attribution.txt diff --git a/docs/source/lang/cpp/comments.rst b/docs/source/lang/cpp/comments.rst deleted file mode 100644 index 1428dc3..0000000 --- a/docs/source/lang/cpp/comments.rst +++ /dev/null @@ -1,64 +0,0 @@ -.. highlight:: cpp - -.. _lang-comments: - -Comments -======== - -Comments are lines in the program that are used to inform yourself or -others about the way the program works. They are ignored by the -compiler, and not exported to the processor, so they don't take up any -space in RAM or Flash. - -One use for comments is to help you understand (or remember) how your -program works, or to inform others how your program works. There are -two different ways of making comments. - -.. _lang-comments-singleline: - -**Single line comment**: Anything following two slashes, ``//``, until -the end of the line, is a comment:: - - x = 5; // the rest of this line is a comment - -.. _lang-comments-multiline: - -**Multi-line comment**: Anything in between a pair of ``/*`` and ``*/`` -is a comment:: - - /* <-- a slash-star begins a multi-line comment - - all of this in the multi-line comment - you can use it to comment - out whole blocks of code - - if (gwb == 0){ // single line comment is OK inside a multi-line comment - x = 3; - } - - // don't forget the "closing" star-slash - they have to be balanced: - */ - -Note that it's okay to use single-line comments within a multi-line -comment, but you can't use multi-line comments within a multi-line -comment. Here's an example:: - - /* ok, i started a multi-line comment - - x = 3; /* this next star-slash ENDS the multi-line comment: */ - - x = 4; // this line is outside of the multi-line comment - - // next line is also outside of the comment, and causes a compile error: - */ - -Programming Tip ---------------- - -When experimenting with code, "commenting out" parts of your program -is a convenient way to remove lines that may be buggy. This leaves -the lines in the code, but turns them into comments, so the compiler -just ignores them. This can be especially useful when trying to locate -a problem, or when a program refuses to compile and the compiler error -is cryptic or unhelpful. - -.. include:: /arduino-cc-attribution.txt diff --git a/docs/source/lang/cpp/comparison.rst b/docs/source/lang/cpp/comparison.rst deleted file mode 100644 index 9cd0a9f..0000000 --- a/docs/source/lang/cpp/comparison.rst +++ /dev/null @@ -1,86 +0,0 @@ -.. highlight:: cpp - -.. _lang-comparison: - -Comparison Operators (``==``, ``!=``, ``<``, ``>``, ``<=``, ``>=``) -=================================================================== - -The comparison operators ``==``, ``!=``, ``<``, ``>``, ``<=``, and -``>=`` are used to compare two numbers. They are :ref:`true -<lang-constants-true>` when the comparison is true, and :ref:`false -<lang-constants-false>` otherwise. They are based on the symbols -=, ≠, <, >, ≤, and ≥ from mathematics. - -Here are some examples, with their meaning in comments:: - - // "eq" is true when x is equal to y - bool eq = (x == y); - - // "neq" is true when x is different than y - bool neq = (x != y); - - // "lt" is true when x is less than, but NOT equal to, y - bool lt = (x < y); - - // "gt" is true when x is greater than, but NOT equal to, y - bool gt = (x > y); - - // "lte" is true when x is less than or equal to y - bool lte = (x <= y); - - // "gte" is true when x is greater than or equal to y - bool gte = (x >= y); - -The parentheses are optional; they are present only for clarity. For -example, the following two lines are the same:: - - bool eq = x == y; - - bool eq = (x == y); - -Uses ----- - -Comparison operators, along with :ref:`boolean operators -<lang-boolean>`, are useful inside the conditionals of :ref:`if -<lang-if>` statements. Here's one example:: - - if (x < 50) { - // only execute these lines if x is less than 50 - SerialUSB.println("delaying:"); - SerialUSB.println(x); - delay(x); - } - -.. warning:: - Beware of accidentally using the single equal sign (``=``) when you - meant to test if two numbers are equal (``==``). This is a common - mistake inside of ``if`` statement conditionals, e.g.:: - - // DON'T MAKE THIS MISTAKE - if (x = 10) { - // body - } - - The single equal sign is the assignment operator, and sets x to 10 - (puts the value 10 into the variable x). Instead use the double equal - sign (e.g. ``if (x == 10)``), which is the comparison operator, and - tests *whether* x is equal to 10 or not. The latter statement is only - true if x equals 10, but the former statement will always be true. - - This is because C evaluates the statement ``if (x=10)`` as follows: 10 - is assigned to x (remember that the single equal sign is the - :ref:`assignment operator <lang-assignment>`), so x now - contains 10. Then the 'if' conditional evaluates 10, which evaluates - to :ref:`true <lang-constants-true>`, since any non-zero number - evaluates to ``true``. - - Consequently, the conditional of an ``if`` statement like ``if (x = - 10) {...}`` will always evaluate to ``true``, and the variable x - will be set to 10, which is probably not what you meant. - - (This sometimes has uses, though, so just because an assignment - appears within a conditional doesn't mean it's automatically wrong. - Be careful to know what you mean.) - -.. include:: /arduino-cc-attribution.txt diff --git a/docs/source/lang/cpp/compoundarithmetic.rst b/docs/source/lang/cpp/compoundarithmetic.rst deleted file mode 100644 index d70a43c..0000000 --- a/docs/source/lang/cpp/compoundarithmetic.rst +++ /dev/null @@ -1,43 +0,0 @@ -.. highlight:: cpp - -.. _lang-compoundarithmetic: - -Compound Arithmetic Operators (``+=`` , ``-=``, ``*=``, ``/=``) -=============================================================== - -These oparators perform a mathematical operation on a variable with -another constant or variable. These operators are just a convenient -shorthand:: - - x += y; // equivalent to the expression x = x + y; - x -= y; // equivalent to the expression x = x - y; - x *= y; // equivalent to the expression x = x * y; - x /= y; // equivalent to the expression x = x / y; - -Here is an example:: - - int x = 2; - int y = 10; - - x += 4; // x now contains 6 - x -= 3; // x now contains 3 - x *= y; // x now contains 30 - x /= 2; // x now contains 15 - x += max(20, 6); // x now contains 35 - x -= sq(5); // x now contains 15 - -Parameters ----------- - -**x**: a numeric variable - -**y**: a numeric variable, number constant, or any other expression -that evaluates to a number (e.g. call to a function that returns a -number). - -See Also --------- - -- :ref:`Arithmetic operators <lang-arithmetic>` - -.. include:: /arduino-cc-attribution.txt diff --git a/docs/source/lang/cpp/compoundbitwise.rst b/docs/source/lang/cpp/compoundbitwise.rst deleted file mode 100644 index 4efe5df..0000000 --- a/docs/source/lang/cpp/compoundbitwise.rst +++ /dev/null @@ -1,229 +0,0 @@ -.. highlight:: cpp - -.. _lang-compoundbitwise: - -Compound Bitwise Operators (``&=``, ``|=``, ``^=``) -=================================================== - -The compound bitwise operators perform their calculations at the -bit level of variables. They are often used to clear and set -specific bits of a variable. - -See the :ref:`bitwise math tutorial <lang-bitwisemath>` for more -information on bitwise operators. - -.. contents:: Contents - :local: - -.. _lang-compoundbitwise-and: - -Compound bitwise AND (``&=``) ------------------------------ - -The compound bitwise AND operator ``&=`` is often used with a variable -and a constant to force particular bits in a variable to be zero. This -is often referred to in programming guides as "clearing" or -"resetting" bits. In a program, writing the line ``x &= y;`` is -equivalent to writing ``x = x & y;``. That is, the value of ``x`` -after the line will be equal to its old value bitwise ANDed with the -value of ``y``:: - - x &= y; // equivalent to x = x & y; - -You can use any integer variable for ``x`` (i.e., any variable of type -``int``, ``char``, ``byte``, ``long long``, etc.). You can use either -an integer variable or any :ref:`integer value -<lang-constants-integers>` (like ``3`` or ``0x20``) for ``y``. - -Before doing an example of ``&=``, let's first review the Bitwise AND -(``&``) operator:: - - 0 0 1 1 operand1 - 0 1 0 1 operand2 - ---------- - 0 0 0 1 (operand1 & operand2) = result - -As shown above, bits that are "bitwise ANDed" with 0 become 0, while -bits that are "bitwise ANDed" with 1 are left unchanged. So, if ``b`` -is a ``byte`` variable, then ``b & B00000000`` equals zero, and ``b & -B11111111`` equals ``b``. - -.. _lang-compoundbitwise-binconst: - -.. note:: The above uses :ref:`binary constants - <lang-constants-integers-bin>`\ . The numbers are still the same - value in other representations, they just might not be as easy to - understand. - - Normally, in C and C++ code, :ref:`hexadecimal - <lang-constants-integers-hex>` or :ref:`octal - <lang-constants-integers-oct>` are used when we're interested in - an integer's bits, rather than its value as a number. - - While hexadecimal and octal literals might be harder to understand - at first, you should really take the time to learn them. They're - part of C, C++, and many other programming languages, while binary - constants are available only for compatibility with Arduino. - - Also, ``B00000000`` is shown for clarity, but zero in any number - format is zero. - -So, to clear (set to zero) bits 0 and 1 of a one-byte variable, while -leaving the rest of the variable's bits unchanged, use the compound -bitwise AND operator ``&=`` with the constant ``B11111100`` -(hexadecimal ``0xFC``\ ):: - - 1 0 1 0 1 0 1 0 variable - 1 1 1 1 1 1 0 0 mask - ---------------------- - 1 0 1 0 1 0 0 0 - ^^^^^^^^^^^^^^^^ ^^^^ - unchanged cleared - - -Here is the same representation with the variable's bits replaced -with the symbol ``x``\ :: - - x x x x x x x x variable - 1 1 1 1 1 1 0 0 mask - ---------------------- - x x x x x x 0 0 - ^^^^^^^^^^^^^^^^ ^^^^ - unchanged cleared - - -So, using a byte variable ``b``\ , if we say:: - - b = B10101010; // B10101010 == 0xAA - b &= B11111100; // B11111100 == 0xFC - -then we will have :: - - b == B10101000; // B10101000 == 0xA8 - -.. _lang-compoundbitwise-or: - -Compound bitwise OR (``|=``) ----------------------------- - -The compound bitwise OR operator ``|=`` is often used with a variable -and a constant to "set" (set to 1) particular bits in a variable. In -a program, writing the line ``x |= y;`` is equivalent to writing ``x = -x | y;``. That is, the value of ``x`` after the line will be equal to -its old value bitwise ORed with the value of ``y``:: - - x |= y; // equivalent to x = x | y; - -You can use any integer variable for ``x`` (i.e., any variable of type -``int``, ``char``, ``long long`` etc.). You can use either an integer -variable or any integer value (like ``3`` or ``0x20``) for ``y``. -(This works the same way as :ref:`compound bitwise AND -<lang-compoundbitwise-and>`\ , ``&=``). - -Before doing an example of ``|=``, let's first review the Bitwise OR -(``|``) operator:: - - 0 0 1 1 operand1 - 0 1 0 1 operand2 - ---------- - 0 1 1 1 (operand1 | operand2) = result - -Bits that are "bitwise ORed" with 0 are unchanged, while bits that are -"bitwise ORed" with 1 are set to 1. So if ``b`` is a ``byte`` -variable, then ``b | B00000000`` equals ``b``, and ``b & B11111111`` -equals ``B11111111`` (here we've used binary constants; see the -:ref:`note <lang-compoundbitwise-binconst>` above). - -So, to set bits 0 and 1 of a one-byte variable, while leaving the rest -of the variable unchanged, use the compound bitwise OR operator -(``|=``) with the constant ``B00000011`` (hexadecimal ``0x3``):: - - 1 0 1 0 1 0 1 0 variable - 0 0 0 0 0 0 1 1 mask - ---------------------- - 1 0 1 0 1 0 1 1 - ^^^^^^^^^^^^^^^^ ^^^^ - unchanged set - -Here is the same representation with the variable's bits replaced with -the symbol ``x``:: - - x x x x x x x x variable - 0 0 0 0 0 0 1 1 mask - ---------------------- - x x x x x x 1 1 - ^^^^^^^^^^^^^^^^ ^^^^ - unchanged set - -So, using a byte variable ``b``, if we say:: - - b = B10101010; // B10101010 == 0xAA - b |= B00000011; // B00000011 == 0x3 - -then we will have :: - - b == B10101011; // B10101011 == 0xAB - -.. _lang-compoundbitwise-xor: - -Compound bitwise XOR (``^=``) ------------------------------ - -The compound bitwise XOR operator ``^=`` is used with a variable and a -constant to "toggle" (change 0 to 1, and 1 to 0) particular bits in a -variable. In a program, writing the line ``x ^= y;`` is equivalent to -writing ``x = x ^ y;``. That is, the value of ``x`` after the line -will be equal to its old value bitwise XORed with the value of ``y``:: - - x ^= y; // equivalent to x = x ^ y; - -You can use any integer variable for ``x`` (i.e., any variable of type -``int``, ``char``, ``long long``, etc.). You can use either an -integer variable or any integer value (like ``3`` or ``0x20``) for -``y``. (This works the same way as :ref:`&= -<lang-compoundbitwise-and>` and :ref:`\|= <lang-compoundbitwise-or>`; -in fact, these three operators all work the same in this way). - -Before doing an example of ``^=``, let's first review the Bitwise -XOR operator, ``^``:: - - 0 0 1 1 operand1 - 0 1 0 1 operand2 - ---------- - 0 1 1 0 (operand1 ^ operand2) = result - -One way to look at bitwise XOR is that each bit in the result is a 1 -if the input bits are different, or 0 if they are the same. Another -way to think about it is that the result bit will be 1 when *exactly* -one (no more, no less) of the input bits is 1; otherwise, it will be -zero. This means that if you XOR a bit with 1, it will change (or -toggle) its value, while if you XOR a bit with 0, it stays the same. - -So, to toggle bits 0 and 1 of a one-byte variable, while leaving the -rest of the variable unchanged, use the compound bitwise XOR operator -``^=`` with the constant ``B00000011`` (hexadecimal ``0x3``\ ; see -:ref:`note <lang-compoundbitwise-binconst>` above):: - - 1 0 1 0 1 0 1 0 variable - 0 0 0 0 0 0 1 1 mask - ---------------------- - 1 0 1 0 1 0 1 1 - ^^^^^^^^^^^^^^^^ ^^^^ - unchanged toggled - -So, using a byte variable ``b``, if we say:: - - b = B10101010; // B10101010 == 0xAA - b ^= B00000011; // B00000011 == 0x3 - -then we will have :: - - b == B10101001; // B10101001 == 0xA9 - -See Also --------- - -- :ref:`Boolean operations <lang-boolean>` (``&&``, ``||``) -- :ref:`Bitwise operators <lang-bitwisemath>` (``&``, ``|``, ``^``, ``~``) - -.. include:: cc-attribution.txt diff --git a/docs/source/lang/cpp/const.rst b/docs/source/lang/cpp/const.rst deleted file mode 100644 index ad0c580..0000000 --- a/docs/source/lang/cpp/const.rst +++ /dev/null @@ -1,50 +0,0 @@ -.. highlight:: cpp - -.. _lang-const: - -``const`` -========= - -The ``const`` keyword stands for "constant". It is a variable -*qualifier* that modifies the behavior of the variable, making a -variable "*read-only*". This means that the variable can be used just -as any other variable of its type, but its value cannot be -changed. You will get a compiler error if you try to assign a value to -a ``const`` variable. - -Constants defined with the ``const`` keyword obey the same rules of -:ref:`variable scoping <lang-scope>` that govern other -variables. This, and the pitfalls of using :ref:`#define -<lang-define>`, often makes using the ``const`` keyword a superior -method for defining constants than ``#define``. - -Example -------- - - :: - - // this defines a variable called "pi", which cannot be changed: - const float pi = 3.14; - float x; - - // .... - - x = pi * 2; // it's fine to find the value of a const variable - - pi = 7; // illegal - you can't write to (modify) a constant - -**#define** or **const** ------------------------- - -You can use either ``const`` or ``#define`` for creating numeric or -string constants. For :ref:`arrays <lang-array>`\ , you will need -to use ``const``. In general, ``const`` is preferred over ``#define`` -for defining constants. - -See Also --------- - -- :ref:`#define <lang-define>` -- :ref:`volatile <lang-volatile>` - -.. include:: /arduino-cc-attribution.txt diff --git a/docs/source/lang/cpp/continue.rst b/docs/source/lang/cpp/continue.rst deleted file mode 100644 index 2a694f6..0000000 --- a/docs/source/lang/cpp/continue.rst +++ /dev/null @@ -1,30 +0,0 @@ -.. highlight:: cpp - -.. _lang-continue: - -``continue`` -============ - -The ``continue`` keyword skips the rest of the current iteration of a -:ref:`while <lang-while>`\ , :ref:`for <lang-for>`\ , or -:ref:`do/while <lang-dowhile>` loop. It continues by checking the -conditional expression of the loop, and proceeding with any subsequent -iterations. - -Example -------- - -:: - - - for (x = 0; x < 255; x ++) { - if (x > 40 && x < 120) { // create jump in values - continue; // skips the next two lines and goes to the - // beginning of the loop, with the next value of x - } - - digitalWrite(PWMpin, x); - delay(50); - } - -.. include:: /arduino-cc-attribution.txt diff --git a/docs/source/lang/cpp/curly-braces.rst b/docs/source/lang/cpp/curly-braces.rst deleted file mode 100644 index df2fe2a..0000000 --- a/docs/source/lang/cpp/curly-braces.rst +++ /dev/null @@ -1,106 +0,0 @@ -.. highlight:: cpp - -.. _lang-curly-braces: - -Curly Braces (``{``, ``}``) -=========================== - -.. contents:: Contents - :local: - -Introduction ------------- - -Curly braces (also referred to as just "braces" or as "curly -brackets") are a major part of the C and C++ programming -languages. They are used in several different constructs, outlined -below, and this can sometimes be confusing for beginners. - -An opening curly brace, ``{`` must always be followed by a closing -curly brace ``}``. This is a condition that is often referred to as -the braces being *balanced*. The Maple IDE (integrated development -environment) includes a convenient feature to check the balance of -curly braces. Just select a brace, or even click the insertion point -immediately following a brace, and its companion will be highlighted\ -[#fbug]_\ . - -Beginning programmers, and programmers coming to C++ from languages -without braces, often find using them confusing or daunting. - -Because the use of the curly brace is so varied, it is good -programming practice to type the closing brace immediately after -typing the opening brace when inserting a construct which requires -curly braces. Then insert some blank lines between your braces and -begin inserting statements. Your braces, and your attitude, will never -become unbalanced. - -Unbalanced braces can often lead to cryptic, impenetrable compiler -errors that can sometimes be hard to track down in a large program. -Because of their varied usages, braces are also incredibly important -to the syntax of a program and moving a brace one or two lines will -usually dramatically affect the meaning of a program. - -The main uses of curly braces ------------------------------ - -**Functions**:: - - // a function body needs braces around it - void myFunction(datatype argument) { - // ... function body goes in here ... - } - -**Loops** (see the :ref:`while <lang-while>`\ , :ref:`for -<lang-for>`\ , and :ref:`do/while <lang-dowhile>` loop reference -pages for more information):: - - // you should put braces around the body of a loop: - - while (boolean expression) { - // code inside the loop goes here - } - - for (initialisation; termination condition; incrementing expr) { - // code inside the loop goes here - } - - do { - // code inside the loop goes here - } while (boolean expression); - - -**Conditional statements** (see the :ref:`if statement <lang-if>` -reference page for more information):: - - // you should put braces around the body of an "if", "else if", - // or "else": - - if (boolean expression) { - // code inside the "if" - } - else if (boolean expression) { - // code inside the "else if" - } - else { - // code inside the "else" - } - -**Switch statements** (see the :ref:`switch statement -<lang-switchcase>` reference page for more information):: - - switch (var) { - case 1: - doThing1(); - break; - case 2: - doThing2(); - break; - } - -.. rubric:: Footnotes - -.. [#fbug] At present this feature is slightly buggy as the IDE will - often find (incorrectly) a brace in text that has been commented - out. - -.. include:: /arduino-cc-attribution.txt diff --git a/docs/source/lang/cpp/define.rst b/docs/source/lang/cpp/define.rst deleted file mode 100644 index b22085f..0000000 --- a/docs/source/lang/cpp/define.rst +++ /dev/null @@ -1,54 +0,0 @@ -.. highlight:: cpp - -.. _lang-define: - -``#define`` -=========== - -``#define`` is a useful C and C++ feature that allows the programmer -to give a name to a constant value before the program is compiled. -The compiler will replace references to these constants with the -defined value at compile time. - -This can have some unwanted side effects. In general, the :ref:`const -<lang-const>` keyword is preferred for defining constants. - -Syntax ------- - -The following line would define the name ``MY_CONSTANT`` to have value -``value``:: - - #define MY_CONSTANT value - -Note that the ``#`` is necessary. It is usually good style for the -name to be capitalized, although this is not required. - -There is no semicolon after the #define statement. If you include one, -the compiler will likely throw cryptic errors in unrelated places. -That is, **don't do this**:: - - // DON'T DO THIS! THE SEMICOLON SHOULDN'T BE THERE! - #define NAME value; - -Similarly, including an equal sign after the ``#define`` line will -also generate a cryptic compiler error further down the page. That -is, **don't do this, either**:: - - // DON'T DO THIS, EITHER! THE EQUALS SIGN SHOULDN'T BE THERE! - #define NAME = value - -Example -------- - - :: - - #define MAPLE_LED_PIN 13 - // The compiler will replace any mention of MAPLE_LED_PIN with - // the value 13 at compile time. - -See Also --------- -- :ref:`const <lang-const>` - -.. include:: /arduino-cc-attribution.txt diff --git a/docs/source/lang/cpp/double.rst b/docs/source/lang/cpp/double.rst deleted file mode 100644 index 59422eb..0000000 --- a/docs/source/lang/cpp/double.rst +++ /dev/null @@ -1,46 +0,0 @@ -.. _lang-double: - -``double`` -========== - -Double precision floating point type. Occupies 8 bytes. On Maple, the -``double`` type has a range of approximately -1.79769×10^308 to -1.79769×10^308; the ``double`` type subject to the same :ref:`overflow -issues <lang-variables-rollover>` as any numeric data type. - -Floating point numbers are not exact, and may yield strange results -when compared. For example ``6.0 / 3.0`` may not equal ``2.0``. You -should instead check that the absolute value of the difference between -the numbers is less than some small number. - -Floating point math is also much slower than integer math in -performing calculations, so should be avoided if, for example, a loop -has to run at top speed for a critical timing function. Programmers -often go to some lengths to convert floating point calculations to -integer math to increase speed. - -For more information, see the `Wikipedia article on floating point -math <http://en.wikipedia.org/wiki/Floating_point>`_\ . - -Floating-point numbers represent numbers with "decimal point", unlike -integral types, which always represent whole numbers. Floating-point -numbers are often used to approximate analog and continuous values -because they have greater resolution than integers. - -The double implementation on the Maple uses twice the number of bytes -as a :ref:`float <lang-float>`, with the corresponding gains in -precision. - -Tip ---- - -Users who borrow code from other sources that includes ``double`` -variables may wish to examine the code to see if the implied range and -precision are different from that actually achieved on the Maple. - -See Also --------- - -- :ref:`float <lang-float>` - -.. include:: /arduino-cc-attribution.txt diff --git a/docs/source/lang/cpp/doublecast.rst b/docs/source/lang/cpp/doublecast.rst deleted file mode 100644 index d3f32ce..0000000 --- a/docs/source/lang/cpp/doublecast.rst +++ /dev/null @@ -1,27 +0,0 @@ -.. highlight:: cpp - -.. _lang-doublecast: - -``double()`` (cast) -=================== - -Converts a value to the :ref:`double <lang-double>` floating point -data type. Here is an example:: - - int x = 2; - double d = double(x); // d now holds 2.0, a double value - -The value ``x`` can be of any type. However, if ``x`` is not a number -(like an ``int`` or ``long long``), you will get strange results. - -See the :ref:`double <lang-double>` reference for details about the -precision and limitations of ``double`` values on the Maple. - -See Also --------- - -- :ref:`double <lang-double>` -- :ref:`float <lang-float>` -- :ref:`float() <lang-floatcast>` - -.. include:: /arduino-cc-attribution.txt diff --git a/docs/source/lang/cpp/dowhile.rst b/docs/source/lang/cpp/dowhile.rst deleted file mode 100644 index d229122..0000000 --- a/docs/source/lang/cpp/dowhile.rst +++ /dev/null @@ -1,26 +0,0 @@ -.. highlight:: cpp - -.. _lang-dowhile: - -``do``/``while`` -================ - -A ``do`` loop works in the same manner as a :ref:`while -<lang-while>` loop, with the exception that the condition is tested -at the end of the loop, so the ``do`` loop will *always* run at least -once. - -This is the basic syntax:: - - do { - // statement block - } while (test condition); - -Example:: - - do { - delay(50); // wait for sensors to stabilize - x = readSensors(); // check the sensors - } while (x < 100); - -.. include:: /arduino-cc-attribution.txt diff --git a/docs/source/lang/cpp/enum.rst b/docs/source/lang/cpp/enum.rst deleted file mode 100644 index b6409eb..0000000 --- a/docs/source/lang/cpp/enum.rst +++ /dev/null @@ -1,52 +0,0 @@ -.. highlight:: cpp - -.. _lang-enum: - -``enum`` -======== - -The ``enum`` keyword is used to specify an enumeration type. An -enumeration type is a type whose values are taken from a specified, -fixed list of constant values. - -Example -------- - -Here's an example defining an enumeration type called ``weather``, -which has values ``HOT``, ``COMFY``, and ``COLD``:: - - enum weather {HOT, COMFY, COLD}; - -Once you've defined this type, you can create variables of type -``weather``, in the same way you would with an :ref:`int <lang-int>`:: - - // create a weather variable named theWeather, with value COMFY: - weather theWeather = COMFY; - -Enumeration types are useful within :ref:`switch statements -<lang-switchcase>`. If you know that an argument is of an enumeration -type, you can make ``case`` statements for all of that type's possible -values, so you know you won't miss anything:: - - void describeWeather(weather currentWeather) { - switch(currentWeather) { - case HOT: - SerialUSB.println("it's hot out"); - break; - case COMFY: - SerialUSB.println("it's nice today"); - break; - case COLD: - SerialUSB.println("it's freezing!"); - break; - } - } - -Such a ``switch`` statement would need no :ref:`default -<lang-switchcase-default>`, since we know that ``currentWeather`` must -be either ``HOT``, ``COMFY``, or ``COLD``. - -See Also --------- - -- :ref:`lang-switchcase` diff --git a/docs/source/lang/cpp/float.rst b/docs/source/lang/cpp/float.rst deleted file mode 100644 index 5195fac..0000000 --- a/docs/source/lang/cpp/float.rst +++ /dev/null @@ -1,50 +0,0 @@ -.. highlight:: cpp - -.. _lang-float: - -``float`` -========= - -Single-precision floating point number. Occupies 4 bytes. On Maple, -the ``float`` type has a range of approximately -3.40282×10^38 to -3.40282×10^38; the ``float`` type is subject to the same -:ref:`overflow issues <lang-variables-rollover>` as any numeric data -type. - -``float``\ s have only 6-7 decimal digits of precision. That means the -total number of digits, not the number to the right of the decimal -point. You can get more precision by using a :ref:`double -<lang-double>` (which has a precision of about 16 decimal digits). - -The following example declares a ``float`` value named ``myfloat``:: - - float myfloat; - -This example declares a ``float`` value named ``sensorCalibrate``, -with value 1.117:: - - float sensorCalibrate = 1.117; - -The general syntax for declaring a float named ``var`` with value -``val`` is:: - - float var = val; - -Here is a more extended example involving a :ref:`float cast -<lang-floatcast>`:: - - int x; - int y; - float z; - - x = 1; - y = x / 2; // y now contains 0, ints can't hold fractions - z = float(x) / 2; // z now contains .5 - -See Also --------- - -- :ref:`double <lang-double>` -- :ref:`Variables <lang-variables>` - -.. include:: /arduino-cc-attribution.txt diff --git a/docs/source/lang/cpp/floatcast.rst b/docs/source/lang/cpp/floatcast.rst deleted file mode 100644 index af92543..0000000 --- a/docs/source/lang/cpp/floatcast.rst +++ /dev/null @@ -1,28 +0,0 @@ -.. highlight:: cpp - -.. _lang-floatcast: - -``float()`` (cast) -================== - -Converts a value to the :ref:`float <lang-float>` data type. Here is -an example (see the :ref:`constants reference <lang-constants-fp>` for -an explanation of the "2.0f"):: - - int x = 2; - float f = float(x); // f now holds 2.0f, a float value - -The value ``x`` can be of any type. However, if ``x`` is not a number -(like an ``int``), you will get strange results. - -See the :ref:`float <lang-float>` reference for details about the -precision and limitations of ``float`` values on the Maple. - -See Also --------- - -- :ref:`float <lang-float>` -- :ref:`double <lang-double>` -- :ref:`double() <lang-doublecast>` - -.. include:: /arduino-cc-attribution.txt diff --git a/docs/source/lang/cpp/for.rst b/docs/source/lang/cpp/for.rst deleted file mode 100644 index 78ea562..0000000 --- a/docs/source/lang/cpp/for.rst +++ /dev/null @@ -1,142 +0,0 @@ -.. highlight:: cpp - -.. _lang-for: - -``for`` -======= - -A ``for`` loop is used to repeat a block of statements enclosed in -curly braces. ``for`` loops are useful for performing repetitive -operations, and are often used in combination with :ref:`arrays -<lang-array>` to operate on collections of data or multiple -:ref:`pins <gpio>`. A ``for`` loop is composed of two parts: first, a -*header*, which sets up the for loop, and then a *body*, which is made -up of lines of code enclosed in curly braces. - -.. contents:: Contents - :local: - -Syntax ------- - -There are three parts to the ``for`` loop header: an *initialization* -expression, *loop condition* expression, and a *post-loop* -expression. The general syntax looks like this:: - - for (initialization; condition; post-loop) { - // all of these lines inside the curly braces are part - // of the loop body. - statement 1; - statement 2; - ... - } - -(Note that there is no semicolon after the post-loop). The -initialization happens first and exactly once, before the loop begins. -Each time through the loop, the condition is tested. The condition is -a :ref:`boolean <lang-boolean>` expression. If it is true, then the -list of statements inside the curly braces are executed. Next, the -post-loop is executed. The loop then begins again by evaluating the -condition again, entering the loop body if it is true. This proceeds -until the condition becomes false. - -Examples --------- - -Here's an example:: - - // Dim an LED using a PWM pin - int pwmPin = 9; // LED in series with 470 ohm resistor on pin 9 - - void setup() { - pinMode(pwmPin, PWM); - } - - void loop() { - for (int i=0; i <= 65535; i++) { - pwmWrite(pwmPin, i); - delay(1); - } - } - -There is a ``for`` loop In the :ref:`loop() <lang-loop>` function of -the above example. This loop starts by declaring an ``int`` variable -named ``i``, whose value starts out at zero. The loop proceeds by -checking if ``i`` is less than or equal to 65535. Since ``i`` is -zero, this is true, and so the calls to :ref:`pwmWrite() -<lang-pwmwrite>` and :ref:`delay() <lang-delay>` happen next. At this -point, the post-loop expression ``i++`` is evaluated, which -:ref:`increments <lang-increment>` ``i``, so that ``i`` becomes one. -That concludes the first time through the loop. Each "time through -the loop" is referred to as an *iteration*. - -The loop then jumps back to the beginning, checking the condition as -the beginning of its second iteration (initialization is skipped, -since this only happens once, before the first iteration). One is -less than 65535, so the loop statements are executed again. This -proceeds over and over until the iteration when ``i`` finally -reaches 65536. At that point, the condition is no longer true, so the -loop stops executing, and the ``loop()`` function returns. - -Here's another example, using a ``for`` loop to brighten and fade an -LED (see the :ref:`pwmWrite() <lang-pwmwrite>` reference for more -information):: - - int pwmPin = 9; // hook up the LED to pin 9 - void loop() { - int x = 1; - for (int i = 0; i >= 0; i += x) { - analogWrite(pwmPin, i); // controls the brightness of the LED - if (i == 65535) { - x = -1; // switch direction, so i starts decreasing - } - delay(1); - } - } - -Coding Tips ------------ - -The C ``for`` loop is more flexible than ``for`` loops found in some -other computer languages, including BASIC. Any or all of the three -header elements may be left blank, although the semicolons are -required. Also the statements for initialization, condition, and -post-loop can be any valid C statements, and use any C datatypes, -including :ref:`floating point numbers <lang-double>`. These types -of unusual ``for`` loops sometimes provide solutions to less-common -programming problems. - -For example, using a multiplication in the post-loop line will -generate a `geometric progression -<http://en.wikipedia.org/wiki/Geometric_progression>`_:: - - for(int x = 1; x <= 100; x = x * 2) { - SerialUSB.println(x); - } - - -This loop prints out the numbers 1, 2, 4, 8, ..., 64. Check -your understanding of ``for`` loops by answering the following two -questions (answers are in footnote [#fanswers]_\ ): - -1. How many iterations occur before the loop finishes? - -2. Why does it stop at 64? - -See Also --------- - -- :ref:`while <lang-while>` loops -- :ref:`do <lang-dowhile>` loops - -.. rubric:: Footnotes - -.. [#fanswers] - 1. Seven. - - 2. After the seventh iteration, the post-loop causes ``x`` to - equal 128. This is larger than 100, so the loop condition is - false, and the loop stops. - - -.. include:: /arduino-cc-attribution.txt diff --git a/docs/source/lang/cpp/goto.rst b/docs/source/lang/cpp/goto.rst deleted file mode 100644 index 2c0b3b0..0000000 --- a/docs/source/lang/cpp/goto.rst +++ /dev/null @@ -1,129 +0,0 @@ -.. highlight:: cpp - -.. _lang-goto: - -Labels and ``goto`` -=================== - -A *label* gives a name to a line of code within a function. You can -label a line by writing a name for it, then a colon (``:``), before -the line starts. The ``goto`` keyword allows program flow to transfer -to a labeled line from anywhere within the same function. - -.. warning:: The use of ``goto`` is discouraged in C and C++ - programming. It is *never necessary* to use ``goto`` to write a - program. - - Unless you know what you're doing, using ``goto`` tends to - encourage code which is harder to debug and understand than - programs without ``goto`` that do the same thing. That said, - however, it's sometimes useful; :ref:`see below <goto-when-to-use>` - for a concrete example. - -Using Labels and goto ---------------------- - -Labels and ``goto`` are probably best explained through example. -Let's start with an example of how to label lines. The first line -(``int x = analogRead(some_pin);``) in the :ref:`loop <lang-loop>` -function below has label ``readpin``. The third line (``delay(x);``) -has label ``startdelay``. The second line (``SerialUSB.println(x);``) -does not have a label:: - - void loop() { - readpin: - int x = analogRead(some_pin); - SerialUSB.println(x); // for debugging - startdelay: - delay(x); - // ... more code ... - } - -Anything which can be a :ref:`variable <lang-variables>` name can -be a label. - -Let's say that we wanted to print ``x`` only if it was very large, say -at least 2000. We might want to do this just so anybody watching on a -:ref:`serial monitor <ide-serial-monitor>` would know they were in for -a longer wait than usual. We can accomplish this through the use of a -``goto`` statement that skips the printing if ``x`` is less than -2000:: - - void loop() { - readpin: - int x = analogRead(some_pin); - if (x < 2000) { - goto startdelay; - } - SerialUSB.println(x); // for debugging - startdelay: - delay(x); - // ... more code ... - } - -In this modified program, whenever ``x`` is less than 2000, the body -of the :ref:`if <lang-if>` statement in the second line is -executed. The ``goto`` statement inside the ``if`` body skips -straight to the line labeled ``startdelay``, passing over the line -doing the printing. - -A ``goto`` does not have to "move forwards"; it can go "backwards", -too. For example, the following program prints "5" forever (why?):: - - void loop() { - printfive: - SerialUSB.println(5); - goto printfive; - SerialUSB.println(6); - } - -.. _goto-when-to-use: - -When to Use goto ----------------- - -As mentioned above, use of ``goto`` is `generally discouraged -<http://en.wikipedia.org/wiki/Goto#Criticism_and_decline>`_. However, -when used with care, ``goto`` can simplify certain programs. One -important use case for ``goto`` is breaking out of deeply nested -:ref:`for <lang-for>` loops or :ref:`if <lang-if>` logic blocks. -Here's an example:: - - for(int r = 0; r < 255; r++) { - for(int g = 255; g > -1; g--) { - for(int b = 0; b < 255; b++) { - if (analogRead(0) > 250) { - goto bailout; - } - // more statements ... - } - // innermost loop ends here - } - } - bailout: - // more code here - -In the above example, whenever the :ref:`analog reading -<lang-analogread>` on pin 0 was greater than 250, the program would -jump to the line labeled ``bailout``, exiting all three loops at once. - -While there is already a :ref:`break <lang-break>` keyword for -breaking out of a loop, it will only break out of the *innermost* -loop. So, if instead of saying "``goto bailout;``", there was a -"``break;``" instead, the program would only exit from the loop with -header "``for(int b = 0; b < 255; b++)``". The program would continue -at the line which reads "``// innermost loop ends here``", which is -clearly undesirable if you wanted to leave all three loops at once. - -More examples of when ``goto`` is a good choice are given in Donald -Knuth's paper, "Structured Programming with go to Statements"; see -below for a link. - -See Also --------- - -- Dijkstra, Edsger W. `Go To Statement Considered Harmful <http://citeseerx.ist.psu.edu/viewdoc/download?doi=10.1.1.92.4846&rep=rep1&type=pdf>`_ (PDF) - -- Knuth, Donald. `Structured Programming with go to Statements <http://pplab.snu.ac.kr/courses/adv_pl05/papers/p261-knuth.pdf>`_ (PDF) - -.. include:: /arduino-cc-attribution.txt diff --git a/docs/source/lang/cpp/if.rst b/docs/source/lang/cpp/if.rst deleted file mode 100644 index f248b05..0000000 --- a/docs/source/lang/cpp/if.rst +++ /dev/null @@ -1,121 +0,0 @@ -.. highlight:: cpp - -.. _lang-if: - -``if``/``else`` -=============== - -An ``if`` statement is used to execute code when certain conditions -are met. The general syntax for an ``if`` statement is:: - - if (condition) { - body - } - -An ``if`` statement first tests whether its *condition* is true (such -as an input being above a certain number). If the condition is true, -the ``if`` statement executes its *body*, which is made up of lines of -code inside :ref:`curly braces <lang-curly-braces>`. If the condition -is false, the body is not executed. Here's a more concrete example:: - - if (someVariable > 50) { - // do something here - } - -The program tests to see if ``someVariable`` is greater than 50. If it -is, the program executes every line in the curly braces (which in the -above example does nothing, since the body is just the :ref:`comment -<lang-comments>` line "``// do something here``"). - -Put another way, if the statement in parentheses is true, the -statements inside the braces are run. If not, the program skips over -the code. - -An ``if`` statement's condition (which is inside the parentheses after -``if``) often uses one or more :ref:`boolean <lang-boolean>` or -:ref:`comparison <lang-comparison>` operators. - -Writing the if Body -------------------- - -The brackets may be omitted after an ``if`` statement's -conditional. If this is done, the next line (which ends in a -semicolon) becomes the only line in the body. The following three -``if`` statements all do the same thing:: - - if (x > 120) digitalWrite(pin, HIGH); - - if (x > 120) - digitalWrite(pin, HIGH); - - if (x > 120) { - digitalWrite(pin, HIGH); - } - -However, the following two examples are different:: - - // example 1: two lines of code in the if body - if (x > 120) { - digitalWrite(pin1, HIGH); - digitalWrite(pin2, HIGH); - } - - // example 2: one line of code in the if body, and - // another line of code after the if statement - if (x > 120) - digitalWrite(pin1, HIGH); // this is in the if body - digitalWrite(pin2, HIGH); // this is NOT in the if body - -In the first example, since the body is enclosed in curly braces, both -lines are included. In the second example, since the curly braces are -missing, only the first line is in the ``if`` body. - -``else`` --------- - -``if``/\ ``else`` allows greater control over the flow of code than -the basic :ref:`if <lang-if>` statement, by allowing multiple tests to -be grouped together. For example, an :ref:`analog input -<lang-analogread>` could be tested, with one action taken if the input -was less than 500, and another action taken if the input was 500 or -greater. The code would look like this:: - - if (pinFiveInput < 500) { - // action A - } else { - // action B - } - -``else`` can precede another ``if`` test, so that multiple, mutually -exclusive tests can be run at the same time. - -Each test will proceed to the next one until a true test is -encountered. When a true test is found, its associated block of code -is run, and the program then skips to the line following the entire -if/else construction. If no test proves to be true, the default -``else`` block is executed, if one is present, and sets the default -behavior. - -Note that an ``else if`` block may be used with or without a -terminating ``else`` block, and vice-versa. An unlimited number of -such ``else if`` branches is allowed. Here is a code example:: - - if (pinFiveInput < 500) { - // do Thing A - } else if (pinFiveInput >= 1000) { - // do Thing B - } else { - // do Thing C - } - -Another way to express branching, mutually exclusive tests, is with a -:ref:`switch/case <lang-switchcase>` statement. - - -See Also --------- - -- :ref:`boolean operators <lang-boolean>` -- :ref:`comparison operators <lang-comparison>` - -.. include:: /arduino-cc-attribution.txt diff --git a/docs/source/lang/cpp/include.rst b/docs/source/lang/cpp/include.rst deleted file mode 100644 index 163509d..0000000 --- a/docs/source/lang/cpp/include.rst +++ /dev/null @@ -1,70 +0,0 @@ -.. highlight:: cpp - -.. _lang-include: - -``#include`` -============ - -``#include`` is used to include outside libraries in your sketch. -This gives the programmer access to a large group of standard C -libraries (groups of pre-made functions and data types), and also -libraries written especially for Maple. - -Example -------- - -This example (from the `Arduino LiquidCrystal Tutorial -<http://arduino.cc/en/Tutorial/LiquidCrystal>`_) includes a library -that is used to control :ref:`LCD displays -<libraries-liquid-crystal>`:: - - // include the library code: - #include <LiquidCrystal.h> - - // initialize the library with the numbers of the interface pins - LiquidCrystal lcd(12, 11, 5, 4, 3, 2); - - void setup() { - // set up the LCD's number of columns and rows: - lcd.begin(16, 2); - // Print a message to the LCD. - lcd.print("hello, world!"); - } - - void loop() { - // set the cursor to column 0, line 1 - // (note: line 1 is the second row, since counting begins with 0): - lcd.setCursor(0, 1); - // print the number of seconds since reset: - lcd.print(millis()/1000); - } - -Note that a ``#include`` line, like :ref:`#define <lang-define>`, -has **no semicolon**. The compiler will print strange error messages -if you add one. - -C Standard Library ------------------- - -The standard C library that comes with Maple is called `newlib -<http://sourceware.org/newlib/>`_. Its main sources of documentation -are its `main reference <http://sourceware.org/newlib/libc.html>`_ -page and its `math functions -<http://sourceware.org/newlib/libm.html>`_ reference page. Here's an -example that imports the math.h library in order to take the `cube -root <http://en.wikipedia.org/wiki/Cube_root>`_ of a number:: - - #include <math.h> - - void setup() { - // no setup necessary - } - - void loop() { - // "cbrt" stands for "cube root" - double cubeRootOf3 = cbrt(3.0); - // prints a number that is approximately the cube root of 3: - SerialUSB.println(cubeRootOf3); - } - -.. include:: /arduino-cc-attribution.txt diff --git a/docs/source/lang/cpp/increment.rst b/docs/source/lang/cpp/increment.rst deleted file mode 100644 index c423d1a..0000000 --- a/docs/source/lang/cpp/increment.rst +++ /dev/null @@ -1,37 +0,0 @@ -.. highlight:: cpp - -.. _lang-increment: - -Increment and Decrement Operators (``++``, ``--``) -================================================== - -These operators increment (add one to) or decrement (subtract one -from) a variable. If they come before the variable, they return its -new value; otherwise, they return its old value. - -Some quick examples:: - - x++; // adds one to x, and returns the old value of x - ++x; // adds one to x, and returns the new value of x - - x--; // decrement x by one and returns the old value of x - --x; // decrement x by one and returns the new value of x - -A more extended example:: - - x = 2; - y = ++x; // x now contains 3, y contains 3 - y = x--; // x contains 2 again, y still contains 3 - -.. warning:: Be careful! You cannot put a space in between the two - ``+`` or ``-`` signs. This example is broken:: - - // this line won't compile (notice the extra space): - int y = x+ +; - -See Also --------- - -- :ref:`lang-compoundarithmetic` - -.. include:: /arduino-cc-attribution.txt diff --git a/docs/source/lang/cpp/int.rst b/docs/source/lang/cpp/int.rst deleted file mode 100644 index fa63946..0000000 --- a/docs/source/lang/cpp/int.rst +++ /dev/null @@ -1,68 +0,0 @@ -.. highlight:: cpp - -.. _lang-int: - -``int`` -======= - -The ``int`` data type represents integers. Integers are your primary -data type for number storage, and store a 4 byte value. This yields a -range of -2,147,483,648 to 2,147,483,647 (minimum value of -2^31 and a -maximum value of (2^31) - 1; that's about negative 2 billion to -positive 2 billion). - -An ``int`` stores a negative number with a technique called `two's -complement math -<http://en.wikipedia.org/wiki/Two%27s_complement#Explanation>`_\ . -The highest bit in an ``int``, sometimes refered to as the "sign" bit, -flags the number as a negative number. (See the linked article on -two's complement for more information). - -The Maple takes care of dealing with negative numbers for you, so that -arithmetic operations work mostly as you'd expect. There can be an -:ref:`unexpected complication <lang-bitshift-signbit-gotcha>` in -dealing with the :ref:`bitshift right operator (>>) -<lang-bitshift>`, however. - -.. _lang-long: - -The ``long`` type is a synonym for ``int``. - -Here is an example of declaring an ``int`` variable named ``pin``, -then giving it value 13:: - - int pin = 13; - -The general syntax for declaring an ``int`` variable named ``var``, -then giving it value ``val``, looks like:: - - int var = val; - -.. _lang-int-overflow: - -Integer Overflow ----------------- - -When ``int`` variables leave the range specified above, they -:ref:`roll over <lang-variables-rollover>` in the other direction. -Here are some examples:: - - int x; - x = -2,147,483,648; - x--; // x now contains 2,147,483,647; rolled over "left to right" - - x = 2,147,483,647; - x++; // x now contains -2,147,483,648; rolled over "right to left" - -See Also --------- - -- :ref:`unsigned int <lang-unsignedint>` -- :ref:`char <lang-char>` -- :ref:`unsigned char <lang-unsignedchar>` -- :ref:`long long <lang-longlong>` -- :ref:`unsigned long long <lang-unsignedlonglong>` -- :ref:`Integer Constants <lang-constants-integers>` -- :ref:`Variables <lang-variables>` - -.. include:: cc-attribution.txt diff --git a/docs/source/lang/cpp/intcast.rst b/docs/source/lang/cpp/intcast.rst deleted file mode 100644 index da838c7..0000000 --- a/docs/source/lang/cpp/intcast.rst +++ /dev/null @@ -1,26 +0,0 @@ -.. highlight:: cpp - -.. _lang-intcast: - -``int()`` (cast) -================ - -Converts a value to the :ref:`int <lang-int>` data type. Here is -an example:: - - double d = 2.5; - int i = int(d); // i holds "2", an int value - -The value inside of the parentheses (``int(...)``) can be of any type. -However, if it is not a numeric type (like ``double``, ``char``, -etc.), you will get strange results. - -See the :ref:`int <lang-int>` reference for details about the -precision and limitations of ``int`` variables on the Maple. - -See Also --------- - -- :ref:`int <lang-int>` - -.. include:: /arduino-cc-attribution.txt diff --git a/docs/source/lang/cpp/keywords.rst b/docs/source/lang/cpp/keywords.rst deleted file mode 100644 index f21cd0d..0000000 --- a/docs/source/lang/cpp/keywords.rst +++ /dev/null @@ -1,204 +0,0 @@ -.. _lang-keywords: - -Keywords -======== - -This page lists all of the C++ keywords, and either links to a -reference page explaining their use, or provides a brief description. - -List of Keywords ----------------- - -The C++ keywords are: - -``and``, ``and_eq``, ``asm``, ``auto``, ``bitand``, ``bitor``, -``bool``, ``break``, ``case``, ``catch``, ``char``, ``class``, -``compl``, ``const``, ``const_cast``, ``continue``, ``default``, -``delete``, ``do``, ``double``, ``dynamic_cast``, ``else``, ``enum``, -``explicit``, ``export``, ``extern``, ``false``, ``float``, ``for``, -``friend``, ``goto``, ``if``, ``inline``, ``int``, ``long``, -``mutable``, ``namespace``, ``new``, ``not``, ``not_eq``, -``operator``, ``or``, ``or_eq``, ``private``, ``protected``, -``public``, ``register``, ``reinterpret_cast``, ``return``, ``short``, -``signed``, ``sizeof``, ``static``, ``static_cast``, ``struct``, -``switch``, ``template``, ``this``, ``throw``, ``true``, ``try``, -``typedef``, ``typeid``, ``typename``, ``union``, ``unsigned``, -``using``, ``virtual``, ``void``, ``volatile``, ``wchar_t``, -``while``, ``xor``, ``xor_eq`` - -Boolean Operator Synonyms -------------------------- - -- ``and`` is a synonym for :ref:`&& <lang-boolean-and>`. -- ``not`` is a synonym for :ref:`\! <lang-boolean-not>`. -- ``not_eq`` is a synonym for :ref:`\!= <lang-comparison>`. -- ``or`` is a synonym for :ref:`|| <lang-boolean-or>`. - -Bitwise Operator Synonyms -------------------------- - -- ``and_eq`` is a synonym for :ref:`&= <lang-compoundbitwise-and>`. -- ``bitand`` is a synonym for (bitwise) :ref:`& <lang-bitwisemath-and>`. -- ``bitor`` is a synonym for :ref:`\| <lang-bitwisemath-or>`. -- ``compl`` is a synonym for :ref:`~ <lang-bitwisemath-not>`. -- ``or_eq`` is a synonym for :ref:`|= <lang-compoundbitwise-or>`. -- ``xor`` is a synonym for :ref:`^ <lang-bitwisemath-xor>`. -- ``xor_eq`` is a synonym for :ref:`^= <lang-compoundbitwise-xor>`. - -Constants ---------- - -- ``true`` and ``false`` are the :ref:`boolean constants - <lang-booleanvariables>`. - -Control Flow ------------- - -- ``break`` can exit out of a :ref:`switch statement - <lang-switchcase>` or a :ref:`for <lang-for>`, :ref:`do - <lang-dowhile>`, or :ref:`while <lang-while>` loop. - -- ``case`` defines alternatives in a :ref:`switch statement <lang-switchcase>`. - -- ``continue`` will move control flow to the next iteration of the - enclosing :ref:`for <lang-for>`, :ref:`do <lang-dowhile>`, or - :ref:`while <lang-while>` loop. - -- ``default`` defines the default alternative in a :ref:`switch - statement <lang-switchcase>`. - -- ``do`` introduces a :ref:`do <lang-dowhile>` loop. - -- ``else`` is used in :ref:`if statements <lang-if>`. - -- ``for`` introduces a :ref:`for <lang-for>` loop. - -- ``goto`` :ref:`jumps <lang-goto>` to a label. - -- ``if`` introduces an :ref:`if statement <lang-if>`. - -- ``return`` :ref:`transfers flow to a function's caller <lang-return>`. - -- ``switch`` introduces a :ref:`switch statement <lang-switchcase>`. - -- ``while`` introduces a :ref:`while <lang-while>` loop. - -Types ------ - -The following keywords are used for built-in types. - -- :ref:`bool <lang-booleanvariables>` -- :ref:`char <lang-char>` -- :ref:`double <lang-double>` -- :ref:`float <lang-float>` -- :ref:`int <lang-int>` -- :ref:`long <lang-long>` -- :ref:`short <lang-built-in-types-integral>` -- :ref:`void <lang-void>` (not really a type, but used in the absence - of one) - -The following keywords are used to introduce new types. - -- :ref:`enum <lang-enum>` - -Qualifiers ----------- - -- :ref:`static <lang-static>` can be used to declare persistent local - variables; it has other uses not documented here. - -- ``unsigned`` is used to specify an unsigned integral type. - Examples: :ref:`lang-unsignedint`, :ref:`lang-unsignedchar`. - -- :ref:`volatile <lang-volatile>` is useful when declaring variables - that may be modified by external interrupts. - -- :ref:`const <lang-const>` is used to define constants. - -Other ------ - -These keywords are not described in the Maple documentation. For more -information, consult a C++ reference. - -- ``asm`` is used to insert literal assembly language. - -- ``auto`` is used to declare that a variable has automatic storage. - -- ``catch`` is used in exception handling. Note that the default - flags we pass to :ref:`GCC <arm-gcc>` include ``-fno-exceptions``. - -- ``class`` is used to define classes. - -- ``const_cast`` is used in typecasting. - -- ``delete`` is used to free ``new``\ -allocated storage. Note that - dynamic memory allocation is not available by default on the Maple, - so you'll have to bring your own ``new`` and ``delete`` if you want - this. - -- ``dynamic_cast`` is used in typecasting. - -- ``explicit`` is used to declare constructors that can be called only - explicitly. - -- ``export`` declares a template definition accessible to other - compilation units. - -- ``extern`` can mark a declaration as a declaration and not a - definition, and also grant external linkage to a ``const`` or - ``typedef``. - -- ``friend`` is used to declare that certain functions have access to - a class's private variables. - -- ``inline`` is a compiler hint to inline a function. - -- ``mutable`` specifies that a member can be updated, even when a - member of a ``const`` object. - -- ``namespace`` declares a new namespace. - -- ``new`` dynamically allocates space for a value. Note that dynamic - memory allocation is not available by default on the Maple, so - you'll have to bring your own ``new`` and ``delete`` if you want - this. - -- ``operator`` is used to define type-specific operator overrides. - -- ``private`` declares a private class member. - -- ``protected`` declares a protected class member. - -- ``public`` declares a public class member. - -- ``register`` is a compiler hint to store a variable in a register. - -- ``reinterpret_cast`` is used in typecasting. - -- ``signed`` is the opposite of ``unsigned``. - -- ``static_cast`` is used in typecasting. - -- ``struct`` declares a new struct. - -- ``template`` introduces a template class, function, etc. - -- ``this`` is a pointer to the receiver object. - -- ``throw`` is used in exception handling. Note that the default - flags we pass to :ref:`GCC <arm-gcc>` include ``-fno-exceptions``. - -- ``try`` is used in exception handling. Note that the default - flags we pass to :ref:`GCC <arm-gcc>` include ``-fno-exceptions``. - -- ``typedef`` defines a type synonym. - -- ``union`` defines an untagged union. - -- ``using`` is a directive related to namespaces. - -- ``virtual`` declares a method which may be overridden. - -- ``wchar_t`` is the wide character type. diff --git a/docs/source/lang/cpp/longcast.rst b/docs/source/lang/cpp/longcast.rst deleted file mode 100644 index 493ad67..0000000 --- a/docs/source/lang/cpp/longcast.rst +++ /dev/null @@ -1,27 +0,0 @@ -.. highlight:: cpp - -.. _lang-longcast: - -``long()`` (cast) -================= - -Converts a value to the :ref:`long <lang-long>` data type. Here is -an example:: - - double d = 2.5; - long i = long(d); // i holds "2L", an long value - -The value inside of the parentheses (``long(...)``) can be of any type. -However, if it is not a numeric type (like ``double``, ``char``, -etc.), you will get strange results. - -See the :ref:`long <lang-long>` reference for details about the -precision and limitations of ``long`` variables on the Maple. - -See Also --------- - -- :ref:`long <lang-long>` -- :ref:`long long <lang-longlong>` - -.. include:: /arduino-cc-attribution.txt diff --git a/docs/source/lang/cpp/longlong.rst b/docs/source/lang/cpp/longlong.rst deleted file mode 100644 index d942cb4..0000000 --- a/docs/source/lang/cpp/longlong.rst +++ /dev/null @@ -1,56 +0,0 @@ -.. highlight:: cpp - -.. _lang-longlong: - -``long long`` -============= - -The ``long long`` data type stores extended size integer values. You -can use a ``long long`` when your values are too large to fit into an -:ref:`int <lang-int>`. A ``long long`` occupies 8 bytes of memory. -This yields a range of approximately -9.2×10^18 to 9.2×10^18 (that's -9.2 billion billion, or about 92 million times the number of stars in -the Milky Way galaxy). The exact range of a ``long long`` on the -Maple is from -9,223,372,036,854,775,808 to 9,223,372,036,854,775,807, -or -2^63 to (2^63-1). A ``long long`` it is subject to the same -:ref:`overflow issues <lang-variables-rollover>` as any numeric data -type. - -A synonym for the ``long long`` type is ``int64``. - -Here's an example of declaring a long long (see :ref:`integer -constants <lang-constants-integers-u-l>` for an explanation of the -"LL" at the end of the number):: - - // Speed of light in nanometers per second (approximate). - long long c = 299792458000000000LL; - -The general syntax for declaring an ``long long`` variable named ``var``, -then giving it value ``val``, looks like:: - - long long var = val; - -This is identical to the ``int`` syntax, with ``long long`` (or, at -your option, ``int64``) replacing ``int``. - -Note that ``long long`` values will still :ref:`overflow -<lang-int-overflow>`, just like ``int`` values, but their much larger -range makes this less likely to happen. - -The downside to using a ``long long`` instead of an ``int`` (besides -the extra storage) is that :ref:`arithmetic <lang-arithmetic>` -operations on ``long long``\ s will take slightly longer than on -``int``\ s. - -See Also --------- - -- :ref:`char <lang-char>` -- :ref:`unsigned char <lang-unsignedchar>` -- :ref:`int <lang-int>` -- :ref:`unsigned int <lang-unsignedint>` -- :ref:`unsigned long long <lang-unsignedlonglong>` -- :ref:`Integer Constants <lang-constants-integers>` -- :ref:`Variables <lang-variables>` - -.. include:: /arduino-cc-attribution.txt diff --git a/docs/source/lang/cpp/modulo.rst b/docs/source/lang/cpp/modulo.rst deleted file mode 100644 index 013d07e..0000000 --- a/docs/source/lang/cpp/modulo.rst +++ /dev/null @@ -1,70 +0,0 @@ -.. highlight:: cpp - -.. _lang-modulo: - -Modulo Operator (``%``) -======================= - -Calculates the `remainder <http://en.wikipedia.org/wiki/Remainder>`_ -when one integer is divided by another. It is useful for keeping a -variable within a particular range (e.g. the size of an array). - -Syntax ------- - -:: - - dividend % divisor - -Parameters ----------- - -**dividend**: the number to be divided - -**divisor**: the number to divide by - -Returns -------- - -The remainder of **dividend**\ /\ **divisor**\ . - -Examples --------- - -:: - - int x; - x = 7 % 5; // x now contains 2 - x = 9 % 5; // x now contains 4 - x = 5 % 5; // x now contains 0 - x = 4 % 5; // x now contains 4 - -:: - - /* update one value in an array each time through a loop */ - - int values[10]; - int i = 0; - - void setup() { - // no setup necessary - } - - void loop() { - values[i] = analogRead(0); - i = (i + 1) % 10; // modulo operator makes sure i stays between 0 and 9 - } - -Tip ---- - -The modulo operator does not work on floats. For that, you can use -the C standard library function `fmod() -<http://sourceware.org/newlib/libm.html#fmod>`_. - -See Also --------- - -- :ref:`Arithmetic <lang-arithmetic>` - -.. include:: /arduino-cc-attribution.txt diff --git a/docs/source/lang/cpp/pointer.rst b/docs/source/lang/cpp/pointer.rst deleted file mode 100644 index ff4ec32..0000000 --- a/docs/source/lang/cpp/pointer.rst +++ /dev/null @@ -1,31 +0,0 @@ -.. _lang-pointer: - -Pointer Operators (``&``, ``*``) -================================ - -The pointer operators ``&`` (reference) and ``*`` (dereference) are -different from the bitwise math operator :ref:`& -<lang-bitwisemath-and>` and the arithmetic operator :ref:`* -<lang-arithmetic>`. - -Pointers are one of the more complicated subjects for beginners in -learning C, and it is possible to write many useful Arduino sketches -without ever encountering pointers. However, for manipulating certain -data structures, the use of pointers can simplify the code, improve -its efficiency, and generally provide many benefits that would be -difficult to achieve without the use of pointers. - -Introducing pointers is somewhat outside the scope of this -documentation. However, a good `pointer tutorial -<http://www.cplusplus.com/doc/tutorial/pointers/>`_ is available. -Also see the `Wikipedia article on pointers -<http://en.wikipedia.org/wiki/Pointer_%28computing%29>`_, especially -the section on `pointers in C -<http://en.wikipedia.org/wiki/Pointer_%28computing%29#C_pointers>`_. - -See Also --------- - -- http://xkcd.com/138/ - -.. include:: /arduino-cc-attribution.txt diff --git a/docs/source/lang/cpp/return.rst b/docs/source/lang/cpp/return.rst deleted file mode 100644 index d9aecbe..0000000 --- a/docs/source/lang/cpp/return.rst +++ /dev/null @@ -1,60 +0,0 @@ -.. highlight:: cpp - -.. _lang-return: - -``return`` -========== - -Terminates a function and return a value from a function to the -calling function, if the function has non-``void`` return type. - -Syntax: -------- - -:: - - // from within a "void" function: - return; - - // from within a non-"void" function: - return value; - -In the second case, ``value`` should have a type which is the same as -the return type of the function, or be convertible to it (like an -``int`` to a ``double``, etc.; see :ref:`this note -<lang-arithmetic-typeconversion>` for some references). - -Examples: ---------- - -A function to compare a sensor input to a threshold:: - - // converts analog readings between 0 and 400 to 0, and 400 up to 1. - int checkSensor() { - if (analogRead(0) > 400) { - return 1; - else { - return 0; - } - } - -An early ``return`` is also useful when testing a section of code -without having to "comment out" large sections of possibly buggy code, -like so:: - - void loop() { - - // brilliant code idea to test here - - return; - - // the rest of a dysfunctional sketch here - // this code will never be executed - } - -See Also --------- - -- :ref:`comments <lang-comments>` - -.. include:: /arduino-cc-attribution.txt diff --git a/docs/source/lang/cpp/scope.rst b/docs/source/lang/cpp/scope.rst deleted file mode 100644 index a270428..0000000 --- a/docs/source/lang/cpp/scope.rst +++ /dev/null @@ -1,120 +0,0 @@ -.. highlight:: cpp - -.. _lang-scope: - -Scope -===== - -Variables in the C++ programming language, which Maple uses (all of -your sketches are C++ programs in disguise), have a property called -*scope*. Simply put, a variable's scope is made up of all of the -lines where the variable can be used. - -Scope in C++ is a fairly complex topic, so we won't try to describe it -in full here. Instead, we present a simplified view, describing two -different kinds of scopes, *global* and *local*. For more detailed -information, consult a C++ reference. - -Global and Local Variables --------------------------- - -A global variable is one that can be "seen" by every function in a -program. In the :ref:`Maple IDE <ide>`, any variable declared outside -of a function (like :ref:`setup() <lang-setup>` and :ref:`loop() -<lang-loop>`) is a global variable. - -A local variable can only be "seen" inside of a particular function. -You can declare a variable to be local to a function by declaring it -inside of the :ref:`curly braces <lang-curly-braces>` which enclose -that function. - -When programs start to get larger and more complex, local variables -are a useful way to ensure that a function has exclusive access to its -own variables. This prevents programming errors when one function -mistakenly modifies variables used by another function. - -It is also sometimes useful to declare and initialize a variable -inside a :ref:`for <lang-for>` loop. This creates a variable that -can only be accessed from inside the loop body. - -Example -------- - -Here is an example sketch (which you can copy into the Maple IDE and -run on your Maple) that illustrates the use of global and local -variables, as well as declaring variables inside of a ``for`` loop. -Be sure to open a :ref:`serial monitor <ide-serial-monitor>` after you -:ref:`verify <ide-verify>` and :ref:`upload <ide-upload>` the sketch:: - - int globalVar; // any function will see this variable - - void setup() { - // since "globalVar" is declared outside of any function, - // every function can "see" and use it: - globalVar = 50; - - // the variables "i" and "d" declared inside the "loop" function - // can't be seen here. see what happens when you uncomment the - // following lines, and try to Verify (compile) the sketch: - // - // i = 16; - // SerialUSB.print("i = "); - // SerialUSB.println(i); - // d = 26.5; - // SerialUSB.print("d = "); - // SerialUSB.println(d); - } - - void loop() { - // since "i" and "d" are declared inside of the "loop" function, - // they can only be seen and used from inside of it: - int i; - double d; - - for (int j = 0; j < 5; j++) { - // variable i can be used anywhere inside the "loop" function; - // variable j can only be accessed inside the for-loop brackets: - i = j * j; - SerialUSB.print("i = "); - SerialUSB.println(i); - } - - // globalVar can be accessed from anywhere. note how even - // though we set globalVar = 50 in the "setup" function, we can - // see that value here: - SerialUSB.print("globalVar = "); - SerialUSB.println(globalVar); - - // d can be accessed from anywhere inside the "loop" function: - d = 26.5; - SerialUSB.print("d = "); - SerialUSB.print(d); - SerialUSB.println(" (before separateFunction())"); - - separateFunction(); - - // notice how even though separateFunction() has a variable - // named "d", it didn't touch our (local) variable which has - // the same name: - SerialUSB.print("d = "); - SerialUSB.print(d); - SerialUSB.println(" (after separateFunction())"); - } - - void separateFunction() { - // variable "d" here has the same name as variable "d" inside of - // the "loop" function, but since they're both _local_ - // variables, they don't affect each other: - double d = 30.5; - SerialUSB.print("d = "); - SerialUSB.print(d); - SerialUSB.println(" (inside of separateFunction())"); - } - -See Also --------- - -- `C++ programming Wikibook <http://en.wikibooks.org/wiki/C%2B%2B_Programming/Programming_Languages/C%2B%2B/Code/Statements/Scope>`_. -- Wikipedia article on `scope <http://en.wikipedia.org/wiki/Scope_%28programming%29>`_ - -.. include:: /arduino-cc-attribution.txt diff --git a/docs/source/lang/cpp/semicolon.rst b/docs/source/lang/cpp/semicolon.rst deleted file mode 100644 index 05e6218..0000000 --- a/docs/source/lang/cpp/semicolon.rst +++ /dev/null @@ -1,22 +0,0 @@ -.. highlight:: cpp - -.. _lang-semicolon: - -Semicolon (``;``) -================= - -Used to end a line of code. Example:: - - int a = 13; - -Tip ---- - -Forgetting to end a line in a semicolon will result in a compiler -error. The error text may be obvious, and refer to a missing -semicolon, or it may not. If an impenetrable or seemingly illogical -compiler error comes up, one of the first things to check is a -missing semicolon, in the immediate vicinity, preceding the line at -which the compiler complained. - -.. include:: /arduino-cc-attribution.txt diff --git a/docs/source/lang/cpp/sizeof.rst b/docs/source/lang/cpp/sizeof.rst deleted file mode 100644 index ec2dea6..0000000 --- a/docs/source/lang/cpp/sizeof.rst +++ /dev/null @@ -1,64 +0,0 @@ -.. highlight:: cpp - -.. _lang-sizeof: - -``sizeof()`` -============ - -The ``sizeof`` operator on the Maple returns the number of bytes -needed to store a value of a given type\ [#fcharsize]_. This can be -an ordinary numeric type, like ``int``. It can be something more -complicated, like a ``struct`` or ``union``. If the argument to -``sizeof`` is an array, it returns the total number of bytes occupied -by the array. - -The general syntax looks like this:: - - sizeof(type) - sizeof(var) - -Example -------- - -The ``sizeof`` operator is useful for dealing with arrays (such as -strings) where it is convenient to be able to change the size of the -array without breaking other parts of the program. - -This program prints out a text string one character at a time. Try -changing the text phrase:: - - char myStr[] = "this is a test"; - int i; - - void setup() { - Serial.begin(9600); - } - - void loop() { - for (i = 0; i < sizeof(myStr) - 1; i++) { - Serial.print(i, DEC); - Serial.print(" = "); - Serial.println(myStr[i], BYTE); - } - } - - -Note that ``sizeof`` returns the total number of bytes. So for larger -variable types such as ``int``, the :ref:`for loop <lang-for>` -would look something like this:: - - for (i = 0; i < (sizeof(myInts)/sizeof(int)) - 1; i++) { - // do something with myInts[i] - } - -.. rubric:: Footnotes - -.. [#fcharsize] Technically (and pedantically) speaking, ``sizeof`` - returns a multiple of the number of bits a ``char`` occupies in - memory. However, on the Maple (this goes for most C++ - implementations), a ``char`` occupies 8 bits = 1 byte. All the C++ - standard guarantees, however, is that a ``char`` occupies at - *least* 8 bits. - -.. include:: /arduino-cc-attribution.txt - diff --git a/docs/source/lang/cpp/sqrt.rst b/docs/source/lang/cpp/sqrt.rst deleted file mode 100644 index fbabf82..0000000 --- a/docs/source/lang/cpp/sqrt.rst +++ /dev/null @@ -1,24 +0,0 @@ -.. _lang-sqrt: - -sqrt() -====== - -Calculates the square root of a number. - -Library Documentation ---------------------- - -.. doxygenfunction:: sqrt - -Arduino Compatibility ---------------------- - -The Maple versino of ``sqrt()`` is compatible with Arduino. - -See Also --------- - -- :ref:`pow <lang-pow>` -- :ref:`sq <lang-sq>` - -.. include:: /arduino-cc-attribution.txt diff --git a/docs/source/lang/cpp/static.rst b/docs/source/lang/cpp/static.rst deleted file mode 100644 index 8c52ba0..0000000 --- a/docs/source/lang/cpp/static.rst +++ /dev/null @@ -1,56 +0,0 @@ -.. highlight:: cpp - -.. _lang-static: - -``static`` -========== - -The ``static`` keyword can be used to create variables that are -visible to only one function. However, unlike local variables that get -created and destroyed every time a function is called, ``static`` -variables persist beyond the function call, preserving their data -between function calls. - -Variables declared as ``static`` will only be created and initialized -the first time a function is called. - -.. note:: This is only one use of the ``static`` keyword in C++. It - has some other important uses that are not documented here; consult - a reliable C++ reference for details. - -Example -------- - -One use case for ``static`` variables is implementing counters that -last longer than the functions which need them, but shouldn't be -shared to other functions. Here's an example:: - - void setup() { - SerialUSB.begin(); - } - - void loop() { - int reading; - if (timeToReadSensors()) { - reading = readSensors(); - } - // do something with reading - } - - int readSensors() { - static int numSensorReadings = 0; - numSensorReadings++; - if (numSensorReadings % 100 == 0) { - SerialUSB.print("just got to another 100 sensor readings"); - } - return analogRead(...); - } - -In this example, the static variable ``numSensorReadings`` is -initialized to zero the first time ``readSensors()`` is called, and -then incremented, so it starts out at one. Subsequent calls to -``readSensors()`` won't reset ``numSensorReadings`` to zero, because -it was declared ``static``. Thus, ``numSensorReadings`` is a count of -the number of times that ``readSensors()`` has been called. - -.. include:: /arduino-cc-attribution.txt diff --git a/docs/source/lang/cpp/string.rst b/docs/source/lang/cpp/string.rst deleted file mode 100644 index 3497484..0000000 --- a/docs/source/lang/cpp/string.rst +++ /dev/null @@ -1,120 +0,0 @@ -.. highlight:: cpp - -.. _lang-string: - -Strings -======= - -Text strings on the Maple can be represented with null-terminated -arrays of type :ref:`char <lang-char>`. - -Examples --------- - -All of the following are valid declarations for strings:: - - char str1[15]; - char str2[6] = {'m', 'a', 'p', 'l', 'e'}; - char str3[6] = {'m', 'a', 'p', 'l', 'e', '\0'}; - char str4[ ] = "maple"; - char str5[6] = "maple"; - char str6[15] = "maple"; - -As you can see, there are several methods available for declaring and -initializing strings: - -- Declare an array of ``char`` without initializing it, as with ``str1``. - -- Declare an array of ``char`` (with one extra ``char``) and the - compiler will add the required null character, as with ``str2``. - -- Explicitly add the null character (``'\0'``), as with ``str3``. - -- Initialize with a string constant in quotation marks (``"..."``); - the compiler will size the array to fit the string constant and a - terminating null character (``str4``). - -- Initialize the array with an explicit size and string constant, - (``str5``). - -- Initialize the array, leaving extra space for a larger string - (``str6``). - -Null Termination ----------------- - -Generally, strings are terminated with a null character (`ASCII -<http://en.wikipedia.org/wiki/ASCII>`_ code 0). This allows functions -(like ``SerialUSB.print()``) to tell where the end of a string is. -Otherwise, they would continue reading subsequent bytes of memory that -aren't actually part of the string. - -This means that your string needs to have space for one more character -than the text you want it to contain. That is why ``str2`` and -``str5`` need to be six characters, even though "maple" is only five --- the last position is automatically filled with a NULL -character. ``str4`` will be automatically sized to six characters, one -for the extra null. In the case of ``str3``, we've explicitly included -the null character (written ``'\0'``) ourselves. - -Note that it's possible to have a string without a final null -character (e.g. if you had specified the length of ``str2`` as five -instead of six). This will break most functions that use strings, so -you shouldn't do it intentionally. If you notice something behaving -strangely (operating on characters not in the string), however, this -could be the problem. - -Single quotes or double quotes? -------------------------------- - -Strings are always defined inside double quotes (``"Abc"``) and -characters are always defined inside single quotes (``'A'``). - -Wrapping long strings ---------------------- - -You can wrap long strings like this:: - - char myString[] = "This is the first line" - " this is the second line" - " etcetera"; - -Arrays of Strings ------------------ - -It is often convenient, when working with large amounts of text, -such as a project with an LCD display, to setup an array of -strings. Because strings themselves are arrays, this is in actually -an example of a two-dimensional array. - -In the code below, the asterisk after the datatype char ``char *`` -indicates that this is an array of "pointers". All array names are -actually pointers, so this is required to make an array of arrays. -Pointers are one of the more esoteric parts of C for beginners to -understand, but it isn't necessary to understand pointers in detail to -use them effectively here:: - - char* myStrings[] = {"This is string 1", "This is string 2", - "This is string 3", "This is string 4", - "This is string 5", "This is string 6"}; - - void setup() { - SerialUSB.begin(); - } - - void loop() { - for (int i = 0; i < 6; i++) { - SerialUSB.println(myStrings[i]); - delay(500); - } - } - - -See Also --------- - -- :ref:`array <lang-array>` -- :ref:`__attribute__ <arm-gcc-attribute-flash>` -- :ref:`Variables <lang-variables>` - -.. include:: /arduino-cc-attribution.txt diff --git a/docs/source/lang/cpp/switchcase.rst b/docs/source/lang/cpp/switchcase.rst deleted file mode 100644 index e31ccf3..0000000 --- a/docs/source/lang/cpp/switchcase.rst +++ /dev/null @@ -1,118 +0,0 @@ -.. highlight:: cpp - -.. _lang-switchcase: - -``switch``\ /\ ``case`` -======================= - -Like :ref:`if <lang-if>` statements, A ``switch`` statement controls -program flow by allowing you to specify different code that should be -executed under various cases. - -The general syntax looks like this:: - - switch (var) { - case val1: - // statements - break; - case val2: - // statements - break; - ... - default: - // statements - } - -Where ``var`` is a variable whose value to investigate, and the -``val1``, ``val2`` after each ``case`` are constant values that -``var`` might be. - -Description ------------ - -A ``switch`` statement compares the value of a variable to the values -specified in ``case`` statements. When a ``case`` statement is found -whose value matches that of the variable, the code in that case -statement is run. - -Here's a more concrete example:: - - switch (var) { - case 1: - doThing1(); - break; - case 2: - doThing2(); - break; - } - afterTheSwitch(); - -In the above example, if ``var == 1``, then the code beginning on the -line after ``case 1`` gets executed. That is, if ``var`` is one, -``doThing1()`` gets called first, and then the ``break`` statement is -executed. - -The ``break`` keyword exits the ``switch`` statement, and is typically -used at the end of each ``case``. Since there is a ``break`` at the -end of ``case 1``, the ``switch`` statement exits, and the next line -to be run is the one which calls ``afterTheSwitch()``. - -Without a ``break``, the ``switch`` statement will continue executing -the following ``case`` expressions ("falling-through") until a -``break`` (or the end of the switch statement) is reached. Let's -pretend the ``switch`` looked like this instead:: - - switch (var) { - case 1: - doThing1(); - // no break statement anymore - case 2: - doThing2(); - break; - } - afterTheSwitch(); - -Now, if ``var`` is one, ``doThing1()`` gets executed like before. -However, without a ``break``, the code would continue to be executed -line-by-line, so ``doThing2()`` would be called next. At this point, -a ``break`` has been reached, so the program continues by calling -``afterTheSwitch()``. This is usually not what you want, which is why -each ``case`` usually has a ``break`` at the end. - -.. _lang-switchcase-default: - -Writing "``default:``" instead of a ``case`` statement allows you to -specify what to do if none of the ``case`` statements matches. Having -a ``default`` is optional (you can leave it out), but if you have one, -it must appear after all of the ``case`` statements. Let's add a -``default`` to the ``switch`` we've been discussing:: - - switch (var) { - case 1: - doThing1(); - break; - case 2: - doThing2(); - break; - default: - doSomethingElse(); - } - afterTheSwitch(); - -If ``var`` is one, then ``doThing1()`` gets called. If ``var`` is -two, ``doThing2()`` gets called. If ``var`` is anything else, -``doSomethingElse()`` gets called. As stated above, a ``default`` is -optional. If you're missing one and none of the ``case`` statements -match, the ``switch`` does nothing at all, as if it weren't there. - -``switch`` statements are often used with an :ref:`enum <lang-enum>` -value as the variable to compare. In this case, you can write down -all of the values the ``enum`` takes as ``case`` statements, and be -sure you've covered all the possibilities. - -See Also: ---------- - -- :ref:`if/else <lang-if>` - -.. include:: /arduino-cc-attribution.txt diff --git a/docs/source/lang/cpp/unsignedchar.rst b/docs/source/lang/cpp/unsignedchar.rst deleted file mode 100644 index 45fedeb..0000000 --- a/docs/source/lang/cpp/unsignedchar.rst +++ /dev/null @@ -1,32 +0,0 @@ -.. highlight:: cpp - -.. _lang-unsignedchar: - -``unsigned char`` -================= - -An unsigned version of the :ref:`char <lang-char>` data type. An -``unsigned char`` occupies 1 byte of memory; it stores an integer from -0 to 255. - -Like an :ref:`unsigned int <lang-unsignedint>`, an ``unsigned char`` -won't store negative numbers; it is also subject to the same -:ref:`overflow issues <lang-int-overflow>` as any integral data type. - -Example -------- - - :: - - unsigned char c = 240; - -See Also --------- - -- :ref:`byte <lang-byte>` -- :ref:`int <lang-int>` -- :ref:`array <lang-array>` -- :ref:`SerialUSB.println() <lang-serialusb-println>` -- :ref:`Serial.println() <lang-serial-println>` - -.. include:: /arduino-cc-attribution.txt diff --git a/docs/source/lang/cpp/unsignedint.rst b/docs/source/lang/cpp/unsignedint.rst deleted file mode 100644 index f8ea473..0000000 --- a/docs/source/lang/cpp/unsignedint.rst +++ /dev/null @@ -1,59 +0,0 @@ -.. highlight:: cpp - -.. _lang-unsignedint: - -``unsigned int`` -================ - -An ``unsigned int`` (unsigned integer) is the same as an :ref:`int -<lang-int>` in that it stores a 4 byte integer value. However, -Instead of storing both negative and positive numbers, an ``unsigned -int`` can only store nonnegative values, yielding a range of 0 to -4,294,967,295 (the positive value is 2^32 - 1). - -The difference between an ``unsigned int`` and a (signed) ``int`` lies -in the way the highest bit, sometimes referred to as the "sign" bit, -is interpreted. In the case of the Maple ``int`` type (which is -signed), if the high bit is a "1", the number is interpreted as a -negative number, using a technique known as `two's complement math -<http://en.wikipedia.org/wiki/Two%27s_complement#Explanation>`_. The -bits in an an ``unsigned int`` are interpreted according to the usual -rules for converting `binary to decimal -<http://en.wikipedia.org/wiki/Binary_numeral_system#Counting_in_binary>`_. - -An ``unsigned int`` is subject to the same :ref:`overflow issues -<lang-int-overflow>` as a regular ``int``; the only difference is -that an ``unsigned int`` will "underflow" at 0, and "overflow" at -4,294,967,295. Here is some example code which illustrates this:: - - unsigned int x; - x = 0; - x--; // x now contains 4,294,967,295; rolled over "left to right" - x++; // x now contains 0; rolled over "right to left" - -.. _lang-unsignedlong: - -The ``unsigned long`` type is a synonym for ``unsigned int``. - -Here is an example of declaring an ``unsigned int`` variable named -``pin``, then giving it value 13:: - - unsigned int pin = 13; - -The general syntax for declaring an ``unsigned int`` variable named -``var``, then giving it value ``val``, looks like:: - - unsigned int var = val; - -See Also --------- - -- :ref:`int <lang-int>` -- :ref:`char <lang-char>` -- :ref:`unsigned char <lang-unsignedchar>` -- :ref:`long long <lang-longlong>` -- :ref:`unsigned long long <lang-unsignedlonglong>` -- :ref:`Integer Constants <lang-constants-integers>` -- :ref:`Variables <lang-variables>` - -.. include:: /arduino-cc-attribution.txt diff --git a/docs/source/lang/cpp/unsignedlonglong.rst b/docs/source/lang/cpp/unsignedlonglong.rst deleted file mode 100644 index a1143f0..0000000 --- a/docs/source/lang/cpp/unsignedlonglong.rst +++ /dev/null @@ -1,43 +0,0 @@ -.. highlight:: cpp - -.. _lang-unsignedlonglong: - -``unsigned long long`` -====================== - -An unsigned version of the :ref:`long long <lang-longlong>` data type. -An ``unsigned long long`` occupies 8 bytes of memory; it stores an -integer from 0 to 2^64-1, which is approximately 1.8×10^19 (18 -quintillion, or 18 billion billion). - -A synonym for the ``unsigned long long`` type is ``uint64``. - -Like an :ref:`unsigned int <lang-unsignedint>`, an ``unsigned long -long`` won't store negative numbers; it is also subject to the same -:ref:`overflow issues <lang-int-overflow>` as any integral data type. - -Here is an example of declaring an ``unsigned long long`` variable -named ``c``, then giving it value 299,792,458,000,000,000 (see -:ref:`integer constants <lang-constants-integers-u-l>` for an -explanation of the "ULL" at the end of the number):: - - // Speed of light in nanometers per second (approximate). - unsigned long long c = 299792458000000000ULL; - -The general syntax for declaring an ``unsigned long long`` variable named -``var``, then giving it value ``val``, looks like:: - - unsigned long long var = val; - -See Also --------- - -- :ref:`long long <lang-longlong>` -- :ref:`int <lang-int>` -- :ref:`unsigned <lang-unsignedint>` -- :ref:`char <lang-char>` -- :ref:`unsigned char <lang-unsignedchar>` -- :ref:`Integer Constants <lang-constants-integers>` -- :ref:`Variables <lang-variables>` - -.. include:: /arduino-cc-attribution.txt diff --git a/docs/source/lang/cpp/variables.rst b/docs/source/lang/cpp/variables.rst deleted file mode 100644 index 9ffdd1d..0000000 --- a/docs/source/lang/cpp/variables.rst +++ /dev/null @@ -1,169 +0,0 @@ -.. highlight:: cpp - -.. _lang-variables: - -Variables -========= - -A variable is a way of naming and storing a value for later use by -the program, such as data from a sensor or an intermediate value -used in a calculation. - -.. contents:: Contents - :local: - -.. _lang-variables-declaring: - -Declaring Variables -------------------- - -Before they are used, all variables have to be *declared*. Declaring a -variable means defining its type, giving it a name, and (optionally) -giving it an initial value (this is often referred to as -*initializing* the variable). Variables do not have to be initialized -(given a value) when they are declared, but it is good style to give -them an initial value whenever possible. - -Here is an example of declaring a variable named ``inputVariable1`` -with type :ref:`int <lang-int>` (the ``int`` type is used to store -integers, like -2, -1, 0, 1, etc.):: - - int inputVariable1; - -In the above declaration, we did not give the variable an initial -value. Here is another example, where we declare an ``int`` variable -named ``inputVariable2``, with an initial value of ``0``:: - - int inputVariable2 = 0; - -The Maple environment comes ready to use with many useful types of -variables. See the :ref:`built-in types <lang-built-in-types>` page -for more information. - -Here are a few examples of declaring variables of different types:: - - int lightSensVal; - char currentLetter; - unsigned long long speedOfLight = 186000ULL; - char errorMessage = {"choose another option"}; // see string - -Naming Variables ----------------- - -The rules for naming a variable are simple. Names for variables can -contain letters, numbers, and underscores (the underscore is the -:kbd:`_` character), and cannot begin with a number. So -``temperature_reading``, ``tempReading``, ``tempReading1``, and -``tempReading2`` are all valid variable names, but ``4_temp_readings`` -is not, because it begins with a number. - -You cannot choose a name for a variable that is one of the C++ -:ref:`keywords <lang-keywords>`. - -Variable names are case-sensitive, so "tempreading" and "tempReading" -are different variables. However, it is very bad style to write code -that chooses variables which are the same up to case. - -You should give your variables descriptive names, so as to make your -code more readable. Variable names like ``tiltSensor`` or -``pushButton`` help you (and anyone else reading your code) understand -what the variable represents. Variable names like ``var`` or -``value``, on the other hand, do little to make your code readable. - -.. _lang-variables-scope: - -Variable Scope --------------- - -An important choice that programmers face is where (in the program -text) to declare variables. The specific place that variables are -declared influences how various functions in a program will "see" the -variable. This is called variable *scope*. See the :ref:`scope -reference <lang-scope>` for more information. - -.. _lang-variables-initializing: - -Initializing Variables ----------------------- - -Variables may be *initialized* (assigned a starting value) when they -are declared or not. It is always good programming practice however to -double check that a variable has valid data in it before it is used. -Using a variable before you give it a value is a common source of -bugs. - -.. _lang-variables-rollover: - -Variable Rollover ------------------ - -Every (numeric) type has a valid *range*. The range of a type is the -smallest and largest value that a variable of that type can store. -For example, the :ref:`int <lang-int>` type has a range of --2,147,483,648 to 2,147,483,647 [#frange]_. - -When variables are made to exceed their range's maximum value, they -"roll over" back to their minimum value. Note that this happens in -both directions. It's like in the game *Pac-Man* -- when Pac-Man goes -past the right edge of the screen, he reappears on the left, and when -he goes past the left side of the screen, he reappears on the right:: - - int x; - x = -2,147,483,648; - x = x - 1; // x now contains -2,147,483,647; rolled over "left to right" - - x = 2,147,483,647; - x = x + 1; // x now contains -2,147,483,648; rolled over "right to left" - -Each numeric type's reference page includes its range. See the -:ref:`built-in types <lang-built-in-types>` reference for links to each -type's reference page. - -Using Variables ---------------- - -Once variables have been declared, they are given values using the -:ref:`assignment operator <lang-assignment>`, which is a single equals -sign, ``=``. The assignment operator tells the program to store the -value on the right side of the equals sign into the variable on the -left side:: - - inputVariable1 = 7; // sets variable named inputVariable1 to 7 - inputVariable2 = analogRead(2); // sets variable named inputVariable2 to - // the (digitized) input voltage read from - // analog pin #2 - -Once a variable has been set (assigned a value), you can test its -value to see if it meets certain conditions, or you can use its value -directly. For instance, the following code tests whether the -inputVariable2 is less than 100, then sets a delay based on -inputVariable2 (which, at that point, is at least 100):: - - if (inputVariable2 < 100) { - inputVariable2 = 100; - } - - delay(inputVariable2); - -See Also --------- - -- :ref:`lang-scope` -- :ref:`lang-built-in-types` - -.. rubric:: Footnotes - -.. [#frange] This range might seem a little weird at first. The - reasons for this range of values have to do with the fact that an - ``int`` occupies 32 bits of memory, and the facts :: - - 2^31 = -2,147,483,648 - 2^31 - 1 = 2,147,483,647 - - - Why 2^31 instead of 2^32? Well, that has to do with `how ints are - (usually) stored - <http://en.wikipedia.org/wiki/Two%27s_complement>`_ on computers. - -.. include:: /arduino-cc-attribution.txt - diff --git a/docs/source/lang/cpp/void.rst b/docs/source/lang/cpp/void.rst deleted file mode 100644 index 7af0acd..0000000 --- a/docs/source/lang/cpp/void.rst +++ /dev/null @@ -1,31 +0,0 @@ -.. highlight:: cpp - -.. _lang-void: - -``void`` -======== - -.. cpp:type:: void - - The ``void`` keyword is used in function declarations. It indicates - that the function is expected to return no information to the - function from which it was called, or that it expects no arguments - from its caller. - -Example -------- - -:: - - // actions are performed in the functions "setup" and "loop" - // but no information is reported to the larger program - - void setup() { - // ... - } - - void loop() { - // ... - } - -.. include:: /arduino-cc-attribution.txt diff --git a/docs/source/lang/cpp/while.rst b/docs/source/lang/cpp/while.rst deleted file mode 100644 index e66e0aa..0000000 --- a/docs/source/lang/cpp/while.rst +++ /dev/null @@ -1,38 +0,0 @@ -.. highlight:: cpp - -.. _lang-while: - -``while`` -========= - -Syntax ------- - -:: - - while (expression) { - // block of code - } - -Description ------------ - -``while`` loops will repeat the statements inside their associated -block of code until the expression inside the parentheses becomes -:ref:`false <lang-constants-false>`. Something must change the tested -expressions' value, or the ``while`` loop will never exit. This could -be in your code, such as an incremented variable, or an external -condition, such as testing a sensor. - -Example -------- - -:: - - var = 0; - while(var < 200) { - // do something repetitive 200 times - var++; - } - -.. include:: /arduino-cc-attribution.txt |