note 4994 modified in functions.variable-functions by irc-html
| From: | irc-html@php.net | Date: | Sat, 19 Jan 2002 19:37:17 +0000 |
| Subject: | note 4994 modified in functions.variable-functions by irc-html | ||
| References: | 1 | Groups: | php.notes |
| Request: | Send a blank email to php-notes+get-25260@lists.php.net to get a copy of this message | ||
an easy way to understand isset and empty is to try the following script:
<?
function VarStat (&$Var) {
if (isset($Var)) echo "\tisset"; else echo "\t";
if (empty($Var)) echo "\tempty"; else echo "\t";
if ($Var) echo "\tself"; else echo "\t";
echo "\t".gettype($Var);
}
echo "\n1 "; VarStat($Hello);
echo "\n2 \"\" "; $Hello=""; VarStat($Hello);
echo "\n3 0 "; $Hello= 0; VarStat($Hello);
echo "\n4 FALSE"; $Hello=FALSE; VarStat($Hello);
echo "\n5 UNSET"; unset($Hello); VarStat($Hello);
echo "\n6 XYZ "; $Hello="XYZ"; VarStat($Hello);
echo "\n6 123 "; $Hello=123; VarStat($Hello);
echo "\n6 0.1 "; $Hello=0.1; VarStat($Hello);
echo "\n7 TRUE "; $Hello=TRUE; VarStat($Hello);
?>
--was--
an easy way to understand isset and empty is to try the following script:
<PRE><?
function VarStat (&$Var) {
if (isset($Var)) echo "\tisset"; else echo "\t";
if (empty($Var)) echo "\tempty"; else echo "\t";
if ($Var) echo "\tself"; else echo "\t";
echo "\t".gettype($Var);
}
echo "\n1 "; VarStat($Hello);
echo "\n2 \"\" "; $Hello=""; VarStat($Hello);
echo "\n3 0 "; $Hello= 0; VarStat($Hello);
echo "\n4 FALSE"; $Hello=FALSE; VarStat($Hello);
echo "\n5 UNSET"; unset($Hello); VarStat($Hello);
echo "\n6 XYZ "; $Hello="XYZ"; VarStat($Hello);
echo "\n6 123 "; $Hello=123; VarStat($Hello);
echo "\n6 0.1 "; $Hello=0.1; VarStat($Hello);
echo "\n7 TRUE "; $Hello=TRUE; VarStat($Hello);
?></PRE>
http://www.php.net/manual/en/functions.variable-functions.php