is_a
(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
Description
bool is_a
( object
$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.
Parameters
-
object -
The tested object
-
class_name -
The class name
-
allow_string -
If this parameter set to
FALSE, string class name asobjectis not allowed. This also prevents from calling autoloader if the class doesn't exist.
Return Values
Returns TRUE if the object is of this class or has this class as one of
its parents, FALSE otherwise.
Changelog
| 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.
|
Examples
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';
}
?>
See Also
- get_class() - Returns the name of the class of an object
- get_parent_class() - Retrieves the parent class name for object or class
- is_subclass_of() - Checks if the object has this class as one of its parents
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