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Home Backend Development PHP Tutorial 关于继承的一点疑惑,希望大家可以帮帮忙!

关于继承的一点疑惑,希望大家可以帮帮忙!

Jun 23, 2016 pm 02:39 PM

class f {
    private $str = "123";
    public function fun() {
         echo $this->str;
    }
}

class s extends f {
    public $str = "abc";
}

$s = new s();
$s->fun();
输出:123


class f {
    public $str = "123";
    public function fun() {
         echo $this->str;
    }
}

class s extends f {
    public $str = "abc";
}

$s = new s();
$s->fun();
输出:abc

第一个的输出很疑惑,为什么会输出父类的属性值?麻烦大家给我分析分析内存,有图说明更好,谢谢大家了。


回复讨论(解决方案)

私有属性不会被继承
私有属性只能用定义它的类的方法访问

私有属性不会被继承
私有属性只能用定义它的类的方法访问

这一点我还是明白,但是我疑惑的地方是,我在子类重新定义了属性,为什么调用方法还是会输出父类的属性值?

私有的是不可侵犯的
私有属性不能被子类覆盖,既然是私有属性不能被继承,当然也就不可能被覆盖了

私有的是不可侵犯的
私有属性不能被子类覆盖,既然是私有属性不能被继承,当然也就不可能被覆盖了
既然没有继承下来,我在子类定义属性也没有问题吧?然后我用继承下来的方法调用本类的属性值,为什么就拿不到呢?反而去拿父类的。不好意思,我还是很疑惑。

既然方法是继承过来的,很自然他会先在自己的地盘里寻找属性?

 解释的我也不清楚。。。。

  刚才百度了一下,明白了 嘿嘿 你看下 这句话   
如果父类有私有的属性。那么父类的方法只为父类的私有属性服务。 

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