Php，即使使用反射，我也无法访问继承的私有变量 [英] Php, I cant access inherited private variables not even with reflection

问题描述

class A
{
    private $a;
}

class B extends A
{
    function __construct()
    {
        (new \ReflectionClass($this))->getProperty('a')->setAccessible(true);
        echo $this->a;
    }
}

(new B());

这应该可以工作，尽管它会触发异常:属性 a 不存在".很多文章都说反射是解决方案

this should work, altough it triggers an exception: "property a doesnt exists". Many articles says Reflection is the sollution

推荐答案

您正在向 ReflectionClass 传递一个 B 的实例，该实例无权访问 <代码>$a.您需要的是将 A 的实例传递给它.这应该有助于澄清您需要在这里做什么

You're passing the ReflectionClass an instance of B, which doesn't have access to $a. What you need is to pass it an instance of A instead. This should help clarify what you need to do here

class A
{
    private $a = 'Bob';
}

class B extends A
{
    function __construct()
    {
        $instance = new A();
        $reflection = new \ReflectionClass($instance);
        $property = $reflection->getProperty('a');
        $property->setAccessible(true);
        echo $property->getValue(new A());
    }
}

(new B());

演示

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