(PHP 4 >= 4.2.0, PHP 5, PHP 7, PHP 8)
is_a — Checks whether the object is of a given type or subtype
Checks if the given object_or_class is of this object type or has
this class as one of its parents.
object_or_classA class name or an object instance.
classThe class or interface name
allow_string
If this parameter set to false, string class name as object_or_class
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.
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
<?php
if ($WF instanceof WidgetFactory) {
echo 'Yes, $WF is a WidgetFactory';
}
?>