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-rw-r--r--source/arduino/const.rst52
1 files changed, 23 insertions, 29 deletions
diff --git a/source/arduino/const.rst b/source/arduino/const.rst
index 295b817..4a45387 100644
--- a/source/arduino/const.rst
+++ b/source/arduino/const.rst
@@ -1,37 +1,35 @@
+.. highlight:: cpp
+
.. _arduino-const:
-const keyword
+const Keyword
=============
-The **const** keyword stands for constant. It is a variable
+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>`_*.
-
+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 <arduino-scope>` that govern other
+variables. This, and the pitfalls of using :ref:`#define
+<arduino-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 use const's in math
+ 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
@@ -39,17 +37,13 @@ Example
**#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:
-
+You can use either ``const`` or ``#define`` for creating numeric or
+string constants. For :ref:`arrays <arduino-array>`\ , you will need
+to use ``const``. In general, ``const`` is preferred over ``#define``
+for defining constants.
-- `#define <http://arduino.cc/en/Reference/Define>`_
-- `volatile <http://arduino.cc/en/Reference/Volatile>`_
+See Also
+--------
+- :ref:`#define <arduino-define>`
+- :ref:`volatile <arduino-volatile>`