# Difference between revisions of "Constant"

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The mathematical value [[Pi|π]] is realized as a function in {{Doc|package=RTL|unit=system|identifier=pi|text=<syntaxhighlight lang="pascal" enclose="none">system.pi</syntaxhighlight>}}. | The mathematical value [[Pi|π]] is realized as a function in {{Doc|package=RTL|unit=system|identifier=pi|text=<syntaxhighlight lang="pascal" enclose="none">system.pi</syntaxhighlight>}}. | ||

− | == | + | == See also == |

* [[Const|<syntaxhighlight lang="pascal" enclose="none">const</syntaxhighlight>]] | * [[Const|<syntaxhighlight lang="pascal" enclose="none">const</syntaxhighlight>]] | ||

* [[Constants]] | * [[Constants]] | ||

+ | * [[Class constants]] |

## Revision as of 08:15, 9 August 2020

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A **constant** is a variable that does not change, it has a final value.

Constants are defined in the `const`

section of a Free Pascal program. When a symbol is defined as constant, the Free Pascal compiler can often do some optimizations to make the output code faster or smaller.

Some special Free Pascal constants are:

Logical truth values

data type limits

The mathematical value π is realized as a function in `system.pi`

.