(PHP 4 >= 4.2.0, PHP 5, PHP 7)
is_a — 锟斤拷锟斤拷锟斤拷锟斤拷锟斤拷诟锟斤拷锟斤拷锟斤拷锟斤拷谴硕锟斤拷锟侥革拷锟斤拷锟津返伙拷 TRUE
$object
, string $class_name
[, bool $allow_string = FALSE
] ) : bool
锟斤拷锟� object 锟角革拷锟斤拷锟斤拷锟斤拷锟角此讹拷锟斤拷母锟斤拷唷�
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.
| 锟芥本 | 说锟斤拷 |
|---|---|
| 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() 锟斤拷锟斤拷
<?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 锟斤拷 PHP 5 锟斤拷使锟斤拷 instanceof 锟斤拷锟斤拷锟�
<?php
if ($WF instanceof WidgetFactory) {
echo 'Yes, $WF is a WidgetFactory';
}
?>