From 210f3d2b1555bae87c9de27ea145e16d3bddb0f8 Mon Sep 17 00:00:00 2001 From: Marti Bolivar Date: Fri, 3 Dec 2010 20:18:00 -0500 Subject: cleaning up previous commits. note that addition of new files under docs/source/lang/api and docs/source/lang/cpp which were just copies of files in docs/source/lang/ imply that change history is lost to git. --- source/lang/boolean.rst | 91 ------------------------------------------------- 1 file changed, 91 deletions(-) delete mode 100644 source/lang/boolean.rst (limited to 'source/lang/boolean.rst') diff --git a/source/lang/boolean.rst b/source/lang/boolean.rst deleted file mode 100644 index 8d6aa5c..0000000 --- a/source/lang/boolean.rst +++ /dev/null @@ -1,91 +0,0 @@ -.. highlight:: cpp - -.. _lang-boolean: - -Boolean Operators -================= - -These can be used inside the condition of an :ref:`if ` -statement. Evaluate to :ref:`true ` or -:ref:`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 - ` ``&`` (single ampersand). They are - entirely different beasts. - - Similarly, do not confuse the boolean OR operator ``||`` (double - pipe) with the :ref:`bitwise OR operator ` - ``|`` (single pipe). - - The :ref:`bitwise NOT operator ` ``~`` - (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 ` (``&``, ``|``, ``^``, ``~``) -- :ref:`Compound bitwise operators ` (``&=``, - ``|=``, ``^=``). -- :ref:`if statement ` - - -.. include:: cc-attribution.txt -- cgit v1.2.3