Difference between revisions of "Constant"
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{{Constant}} | {{Constant}} | ||
| − | A '''constant''' is a variable that does not change, it has a final value. | + | A '''constant''' is a [[Variable|variable]] that does not change, it has a final value. |
| − | Constants are defined in the [[Const#Const_Section|<code>const</code> section]] of a Free Pascal program. When a symbol is defined as constant, the [[Compiler|Free Pascal compiler]] can often do some optimizations to make the output code faster or smaller. | + | Constants are defined in the [[Const#Const_Section|<code>const</code> section]] of a [[FPC|Free Pascal]] [[Program|program]]. When a symbol is defined as constant, the [[Compiler|Free Pascal compiler]] can often do some optimizations to make the output code faster or smaller. |
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data type limits | data type limits | ||
| − | * [[Nil|<syntaxhighlight lang="pascal" enclose="none">nil</syntaxhighlight>]]: empty pointer value | + | * [[Nil|<syntaxhighlight lang="pascal" enclose="none">nil</syntaxhighlight>]]: empty [[Pointer|pointer]] value |
* [[maxint|<syntaxhighlight lang="pascal" enclose="none">maxint</syntaxhighlight>]]: largest possible [[Integer|<syntaxhighlight lang="pascal" enclose="none">integer</syntaxhighlight>]] value | * [[maxint|<syntaxhighlight lang="pascal" enclose="none">maxint</syntaxhighlight>]]: largest possible [[Integer|<syntaxhighlight lang="pascal" enclose="none">integer</syntaxhighlight>]] value | ||
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* [[Const|<syntaxhighlight lang="pascal" enclose="none">const</syntaxhighlight>]] | * [[Const|<syntaxhighlight lang="pascal" enclose="none">const</syntaxhighlight>]] | ||
* [[Constants]] | * [[Constants]] | ||
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Revision as of 21:40, 28 June 2019
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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.
