Rechercher une fonction PHP

defined

(PHP 4, PHP 5, PHP 7)

definedChecks whether a given named constant exists

Description

bool defined ( string $name )

Checks whether the given constant exists and is defined.

Note:

If you want to see if a variable exists, use isset() as defined() only applies to constants. If you want to see if a function exists, use function_exists().

  

Parameters

name

The constant name.

  

Return Values

Returns TRUE if the named constant given by name has been defined, FALSE otherwise.

  

Examples

Example #1 Checking Constants

<?php
/* Note the use of quotes, this is important.  This example is checking
 * if the string 'TEST' is the name of a constant named TEST */
if (defined('TEST')) {
    echo 
TEST;
}
?>

  

See Also

Find a PHP function

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Document created the 30/01/2003, last modified the 26/10/2018
Source of the printed document:https://www.gaudry.be/nl/en/php-rf-function.defined.html

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References

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