instanceof

php关键字：instanceof

判断一个对象是否是某一个类的实例

<?phpabstract class Test{    abstract function func1();}interface TestInterface{    public function func2();}class a extends Test implements TestInterface{    public function func1()    {        echo __METHOD__;    }        public function func2()    {        echo __METHOD__;    }}$cls = new a;var_dump($cls instanceof Test);             // truevar_dump($cls instanceof TestInterface);    // truevar_dump($cls instanceof a);                // true?>