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php $this赋值的问题

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Release: 2016-06-06 20:39:16
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<code><?php class A{
    public $a = 1;
    function aa(){
        $b = $this;
        echo $b->a;   //输出1
        $this->a = 2;
        echo $b->a;  //输出2 
    }
}
</code>
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想知道第二次输出为么是2????

回复内容:

<code><?php class A{
    public $a = 1;
    function aa(){
        $b = $this;
        echo $b->a;   //输出1
        $this->a = 2;
        echo $b->a;  //输出2 
    }
}
</code>
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想知道第二次输出为么是2????

http://php.net/manual/zh/language.oop5.references.php
对象和引用

这个问题的核心在于: 你不了解PHP是怎么传值的。去了解一下吧, 顺便把&符号, 类的__clone魔术方法搞明白。

上面输出2的原因是因为php传递对象默认传递的是引用。

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