看到这里就停止了 ，没有看懂作业

摘要：<?php//单例模式：一个来仅允许被实例化一次class Wife{}$wife1 = new Wife;$wife2 = new Wife;echo ($wife1 instanceof Wife)?'是':'不是';echo '<br>';echo ($wife2 instanceof Wife)?'是':&#

<?php
//单例模式：一个来仅允许被实例化一次
class Wife
{

}

$wife1 = new Wife;
$wife2 = new Wife;

echo ($wife1 instanceof Wife)?'是':'不是';
echo '<br>';
echo ($wife2 instanceof Wife)?'是':'不是';
echo '<br>';
echo ($wife1 === $wife2)? '完全相等':'不相等';
echo '<br>';
var_dump($wife1,$wife2);