(PHP 4, PHP 5, PHP 7)
is_resource — Finds whether a variable is a resource
varThe variable being evaluated.
Returns TRUE if var is a resource,
FALSE otherwise.
Example #1 is_resource() example
<?php
$db_link = @mysql_connect('localhost', 'mysql_user', 'mysql_pass');
if (!is_resource($db_link)) {
die('Can\'t connect : ' . mysql_error());
}
?>
Note:
is_resource() is not a strict type-checking method: it will return
FALSEifvaris a resource variable that has been closed.