ReflectionClass
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ReflectionClass::isInstance

(PHP 5)

ReflectionClass::isInstance — Checks class for instance

说明

public bool ReflectionClass::isInstance ( object $object )

Checks if an object is an instance of a class.

参数

object

The object being compared to.

返回值

成功时返回 TRUE， 或者在失败时返回 FALSE.

范例

Example #1 ReflectionClass::isInstance() related examples

<?php
// Example usage
$class = new ReflectionClass('Foo');

if ($class->isInstance($arg)) {
    echo "Yes";
}

// Equivalent to
if ($arg instanceof Foo) {
    echo "Yes";
}

// Equivalent to
if (is_a($arg, 'Foo')) {
    echo "Yes";
}
?>

以上例程的输出类似于：

Yes
Yes
Yes

参见

ReflectionClass
在线手册：中文 英文
PHP手册
PHP手册 - N: Checks class for instance

用户评论:

Peter Kruithof (12-Jul-2010 02:21)

This function has a flaw in PHP versions < 5.3.* (my tested version was 5.3.2), in which class inheritance is not handled properly. The following test case renders true in 5.3.2, but false on 5.2.9:

<?php
class A {
}

class B extends A {
    public function foo(A $a) {
    }
}

$b = new B();

$class = new ReflectionClass('B');
$method = $class->getMethod('foo');
$parameters = $method->getParameters();
$param = $parameters[0];
$class = $param->getClass();

var_dump($class->isInstance($b));
?>

If you're running a PHP version lower than 5.3, my suggestion is to use the following fix:

<?php
[...]

$param = $parameters[0];
$class = $param->getClass();
$classname = $class->getName();

var_dump($b instanceof $classname);
?>