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author | Marti Bolivar <mbolivar@mit.edu> | 2010-12-21 10:27:37 -0500 |
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committer | Marti Bolivar <mbolivar@mit.edu> | 2010-12-21 10:27:37 -0500 |
commit | c45bccad44187da27505cf5808424e709e3f54a1 (patch) | |
tree | 18a459a50f8d0551ba046e30462c93999d982725 /docs/source/arduino/const.rst | |
parent | 84fd2532a7f23d20354ff590790b3f892cb7e7d7 (diff) | |
parent | d5ad2a27f4e69e6cc9324331945937c983c30366 (diff) | |
download | librambutan-c45bccad44187da27505cf5808424e709e3f54a1.tar.gz librambutan-c45bccad44187da27505cf5808424e709e3f54a1.zip |
Merge branch 'master' into debug-serialusb.
Chose debug-serialusb version in cases of conflict.
Conflicts:
libmaple/usb/usb_callbacks.c
Diffstat (limited to 'docs/source/arduino/const.rst')
-rw-r--r-- | docs/source/arduino/const.rst | 55 |
1 files changed, 0 insertions, 55 deletions
diff --git a/docs/source/arduino/const.rst b/docs/source/arduino/const.rst deleted file mode 100644 index 295b817..0000000 --- a/docs/source/arduino/const.rst +++ /dev/null @@ -1,55 +0,0 @@ -.. _arduino-const: - -const keyword -============= - -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 rules of -*`variable scoping <http://arduino.cc/en/Reference/Scope>`_* that -govern other variables. This, and the pitfalls of using*#define*, -makes the *const* keyword a superior method for defining constants -and is preferred over using -*`#define <http://arduino.cc/en/Reference/Define>`_*. - - - -Example -------- - -:: - - const float pi = 3.14; - float x; - - // .... - - x = pi * 2; // it's fine to use const's in math - - 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 -`arrays <http://arduino.cc/en/Reference/Array>`_, you will need to -use **const**. In general *const* is preferred over *#define* for -defining constants. - - - -See also: - - -- `#define <http://arduino.cc/en/Reference/Define>`_ -- `volatile <http://arduino.cc/en/Reference/Volatile>`_ - |