From 5e587be27a7c3bd854b686952a5c9637a2432ff0 Mon Sep 17 00:00:00 2001 From: Marti Bolivar Date: Sun, 28 Nov 2010 11:23:33 -0500 Subject: reorganized all the arduino/ docs into a lang/ subdirectory since they're properly CC attributed now. --- docs/source/arduino/const.rst | 52 ------------------------------------------- 1 file changed, 52 deletions(-) delete mode 100644 docs/source/arduino/const.rst (limited to 'docs/source/arduino/const.rst') diff --git a/docs/source/arduino/const.rst b/docs/source/arduino/const.rst deleted file mode 100644 index b008144..0000000 --- a/docs/source/arduino/const.rst +++ /dev/null @@ -1,52 +0,0 @@ -.. highlight:: cpp - -.. _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 same rules of -:ref:`variable scoping ` that govern other -variables. This, and the pitfalls of using :ref:`#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 `\ , you will need -to use ``const``. In general, ``const`` is preferred over ``#define`` -for defining constants. - -See Also --------- - -- :ref:`#define ` -- :ref:`volatile ` - - -.. include:: cc-attribution.txt -- cgit v1.2.3