note 96098 modified in language.references.pass by danbrown
| From: | danbrown@php.net | Date: | Mon, 08 Feb 2010 22:16:31 +0000 |
| Subject: | note 96098 modified in language.references.pass by danbrown | ||
| References: | 1 | Groups: | php.notes |
| Request: | Send a blank email to php-notes+get-165767@lists.php.net to get a copy of this message | ||
Watch out that passing an uninitialised variable to a function will create the variable and will NOT
give a NOTICE-undefined variable:
<?php
function ifnull(&$v,$default) {
if (isset($v)) return $v;
return $default;
}
$p=array();
$p['apple']=3;
echo ifnull($p['apple'],4); -> 3
echo ifnull($p['pear'],5); -> 5 No "undefined index" here.
if (isset($p['pear'])) echo "pear is set"; else echo "pear not set";
-> not set
if (array_key_exists('pear',$p)) echo "pear exists"; else echo "pear
doesn't exist"; -> pear exists!
?>
--was--
Watch out that passing an uninitialised variable to a function will create the variable and will NOT
give a NOTICE-undefined variable:
function ifnull(&$v,$default) {
if (isset($v)) return $v;
return $default;
}
$p=array();
$p['apple']=3;
echo ifnull($p['apple'],4); -> 3
echo ifnull($p['pear'],5); -> 5 No "undefined index" here.
if (isset($p['pear'])) echo "pear is set"; else echo "pear not set";
-> not set
if (array_key_exists('pear',$p)) echo "pear exists"; else echo "pear
doesn't exist"; -> pear exists!
http://php.net/manual/en/language.references.pass.php