(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.
object
The tested object
class_name
The 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';
}
?>