note 24164 added to language.types.null
| From: | php-general at lists dot php dot net | Date: | Thu, 08 Aug 2002 11:21:30 +0000 |
| Subject: | note 24164 added to language.types.null | ||
| Groups: | php.notes | ||
| Request: | Send a blank email to php-notes+get-34522@lists.php.net to get a copy of this message | ||
No,
They are NOT the same:
$var1 = "test1";
$var2 = "test2";
unset($var1);
$var2 = NULL;
if (isset($var1)) { echo "var1 is set.<br>\n"; } else { echo "var1 is not
set.<br>\n"; }
if (isset($var2)) { echo "var2 is set.<br>\n"; } else { echo "var2 is not
set.<br>\n"; }
if (array_key_exists("var1", $GLOBALS)) { echo "var1 exist.<br>\n"; } else
{ echo "var1 don't exist.<br>\n"; }
if (array_key_exists("var2", $GLOBALS)) { echo "var2 exist.<br>\n"; } else
{ echo "var2 don't exist.<br>\n"; }
The ouput will be something:
var1 is not set.<br>
var2 is not set.<br>
var1 don't exist.<br>
var2 exist.<br>
--
http://www.php.net/manual/en/language.types.null.php
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