note 83352 deleted from function.get-defined-constants by felipe
| From: | felipe@php.net | Date: | Fri, 23 May 2008 23:46:57 +0000 |
| Subject: | note 83352 deleted from function.get-defined-constants by felipe | ||
| References: | 1 | Groups: | php.notes |
| Request: | Send a blank email to php-notes+get-139668@lists.php.net to get a copy of this message | ||
Note Submitter: chris dot jacob at marksydney dot com
Reason: 1
----
How to: only define a USER constant if it hasn't already been defined.
<?php
// fetch an array of all the defined constants
$tDefinedConstantsArray = get_defined_constants(true);
// define a user constant if it does not already exist
// (i.e. does not exist as a KEY in the USER defined constants; within the defined contants array)
if(array_key_exists('MY_CONSTANT', $tDefinedConstantsArray['user']) == false)
{
define("MY_CONSTANT", "some value");
}
?>