(PHP 4 >= 4.2.0, PHP 5, PHP 7)
is_a — Checks if the object is of this class or has this class as one of its parents
Checks if the given object is of this class or has
this class as one of its parents.
objectA class name or an object instance.
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.
Beispiel #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";
}
?>
Beispiel #2 Using the instanceof operator in PHP 5
<?php
if ($WF instanceof WidgetFactory) {
echo 'Yes, $WF is a WidgetFactory';
}
?>