什么是PHP函数重载? [英] What is PHP function overloading for?

问题描述

在Java之类的语言中，可以通过以下方式使用重载:

In languages like Java, overloading can be used in this way:

void test($foo, $bar){}
int test($foo){}

然后，如果您使用2个参数(例如test($x, $y);)调用了test()，则将调用第一个函数.如果仅传递了1个参数，例如test($x);，则将调用第二个函数.

Then if you called test() with 2 arguments e.g test($x, $y);, the first function would be called. If you passed only 1 argument e.g test($x);, the 2nd function would be called.

从手册中看来，php 5确实有重载，但是它的作用是什么?我似乎无法理解有关此主题的手册.

From the manual it seems that php 5 does have overloading, but what is it for? I can't seem to understand the manual on this topic..

推荐答案

PHP的重载含义与Java的不同.在PHP中，重载意味着您​​可以通过实现

PHP's meaning of overloading is different than Java's. In PHP, overloading means that you are able to add object members at runtime, by implementing some of the __magic methods, like __get, __set, __call, __callStatic. You load objects with new members.

PHP中的重载提供了以下方法: 动态地创建"属性并 方法.这些动态实体是 通过魔术方法可以处理 建立各种课程 动作类型.

Overloading in PHP provides means to dynamically "create" properties and methods. These dynamic entities are processed via magic methods one can establish in a class for various action types.

一个例子:

class Foo
{
    public function __call($method, $args)
    {
        echo "Called method $method";
    }
}

$foo = new Foo;

$foo->bar(); // Called method bar
$foo->baz(); // Called method baz

顺便说一句，自PHP 4.3.0起，PHP就支持这种重载.唯一的区别是，在PHP 5之前的版本中，您必须使用

And by the way, PHP supports this kind of overloading since PHP 4.3.0. The only difference is that in versions prior to PHP 5 you had to explicitly activate overloading using the overload() function.

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