parent :: method()-调用非静态方法 [英] parent::method() - calling non static method

问题描述

我不了解在PHP中调用父方法的概念. 父方法不是静态的，但会被静态调用-通常，PHP会引发错误/警告.

I don't understand the concept of calling a parent method in PHP. The parent method is not static, yet it is called statically - normally PHP would throw an error/warning.

问题是，这是PHP的一个怪癖，还是在OOP中应该是这样?

以php.net为例:

Taking the example from php.net:

<?php
class A {
    function example() {
        echo "I am A::example() and provide basic functionality.<br />\n";
    }
}

class B extends A {
    function example() {
        echo "I am B::example() and provide additional functionality.<br />\n";
        parent::example();
    }
}

$b = new B;

// This will call B::example(), which will in turn call A::example().
$b->example();
?>

http://php.net/manual/en/keyword.parent.php

在PHP 5中，调用非静态方法静态生成E_STRICT 液位警告.

In PHP 5, calling non-static methods statically generates an E_STRICT level warning.

http://php.net/manual/en/language.oop5. static.php

推荐答案

如果您要查看

If you will look at the definition of static method you will see:

1. 静态方法旨在与类的所有实例相关，而不是与任何特定实例相关.-实际上，此方法与父类的所有子级都相关.
2. 即使该类的实例尚不存在，也可以调用静态方法.-同样，您永远不会创建父类的实例来调用该方法.

1. Static methods are meant to be relevant to all the instances of a class rather than to any specific instance. - indeed this method is relevant to all children of the parent class.
2. A static method can be invoked even if no instances of the class exist yet. - again, you never create an instance of the parent class to invoke the method.

因此，我们可以将此参数作为 PHP 的借口.顺便说一下，在 C ++ 中，它是通过相同的方式完成的.

So we can take this argument as an excuse for PHP. By the way, in C++ it is done the same way.

但是还有其他语言，就像您所说的那样.例如，在 JAVA 中，称为super.printMethod();的父方法在 C#中类似于base.printMethod().

But there are other languages, where it is done like you said. For example, in JAVA, the parent method called like super.printMethod();, in C#, it is done like base.printMethod().

因此在 PHP 中，为简化解析器可能会这样做，因为对于这种调用parent->printMethod()，它们将需要特定的边沿大小写.

So in PHP it might be done for the parser simplicity, as they will need a specific edge case for such invocation parent->printMethod().

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