PHP可以static ::代替self ::吗? [英] PHP Can static:: replace self::?

问题描述

我对此事有点困惑.我正在设计一个ORM类，它的行为与ActiveRecord在ruby on rails上非常相似，但这不重要.

I am a little confused with this matter. I am designing an ORM class that tries to behave very similarly to ActiveRecord in ruby on rails, but that's beside the point.

我要说的是，我的类广泛使用静态属性继承，特别是用于数据库和表处理.我的问题是，我应该完全使用self ::吗?

What I'm trying to say is that my class makes extensive use of static attribute inheritance, specially for database and table handling. My question is, should I use self:: at all?

推荐答案

您必须问自己:我要采用适当的方法来解决问题吗?"

You have to ask yourself: "Am I targeting the problem with the adequated approach?"

self::和static::做两个不同的事情.例如，self::或__CLASS__是对当前类的引用，因此在一定范围内进行定义将无法满足对向前进行静态调用的需要.

self:: and static:: do two different things. For instance self:: or __CLASS__ are references to the current class, so defined in certain scope it will NOT suffice the need of static calling on forward.

继承会发生什么?

class A {
    public static function className(){
        echo __CLASS__;
    }

    public static function test(){
        self::className();
    }
}

class B extends A{
    public static function className(){
        echo __CLASS__;
    }
}

B::test();

这将打印

A

另一方面，它具有预期的行为

In the other hand with static:: It has the expected behaviour

class A {
    public static function className(){
        echo __CLASS__;
    }

    public static function test(){
        static::className();
    }
}

class B extends A{
    public static function className(){
        echo __CLASS__;
    }
}


B::test();

这将打印

B

这称为 后期静态绑定在PHP 5.3.0中.它解决了调用在运行时引用的类的局限性.

That is called late static binding in PHP 5.3.0. It solves the limitation of calling the class that was referenced at runtime.

考虑到这一点，我认为您现在可以充分看到并解决问题了.如果您要继承几个静态成员，并且需要访问父成员和子成员，则self::将无法满足要求.

With that in mind I think you can now see and solve the problem adequately. If you are inheriting several static members and need access to the parent and child members self:: will not suffice.

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