(PHP 4 >= 4.2.0, PHP 5)
is_a — Checks if the object is of this class or has this class as one of its parents
$object , string $class_name [, bool $allow_string = FALSE ] ) Checks if the given object is of this class or has this class as one of its parents.
objectThe tested object
class_nameThe class name
allow_string If this parameter set to false, string class name as object is not allowed. This also prevents from calling autoloader if the class doesn't exist.
Returns TRUE if the object is of this class or has this class as one of its parents, FALSE otherwise.
| Version | Description |
|---|---|
| 5.3.9 | Added allow_string parameter |
| 5.3.0 | This function is no longer deprecated, and will therefore no longer throw E_STRICT warnings. |
| 5.0.0 | This function became deprecated in favour of the instanceof operator. Calling this function will result in an E_STRICT warning. |
Example #1 is_a() example
<?php
// define a class
class WidgetFactory
{
var $oink = 'moo';
}
// create a new object
$WF = new WidgetFactory();
if (is_a($WF, 'WidgetFactory')) {
echo "yes, \$WF is still a WidgetFactory\n";
}
?> Example #2 Using the instanceof operator in PHP 5
<?php
if ($WF instanceof WidgetFactory) {
echo 'Yes, $WF is a WidgetFactory';
}
?>