php_demo/07面向对象/10判断对象是否属于某个类.php

<?php
    class A {}
    class B {}

    $obj = new A;

    $ret=$obj instanceof B;
    echo $ret.'<br>';
    if($obj instanceof B){
        echo 'true'.'<br>';
    }else{
        echo 'false'.'<br>';
    }

    $ret=$obj instanceof A;
    echo $ret.'<br>';
?>