PHP按值传递对象 [英] PHP pass objects by value

问题描述

我想用PHP实现一个纯函数

I'd like to implement a pure function in PHP

如何通过值而不是通过引用传递对象?

How do I pass an object by value and not by reference?

换句话说，这是预期的输出:

In other words, this is the expected output:

function change($obj) {
    $obj->set_value(2);
}

$obj = new Object();
$obj->set_value(1);
change($obj);
echo $obj->get_value(); // 1

推荐答案

在此处阅读:

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

您真的不应该按值传递，因为那样就需要深层复制.深度克隆，或为参数分配的疯狂数量.

you really shouldn't pass by value, as that would require a deep copy aka. deep clone, or an insane amount allocated for for parameters..

如果您确实想要，答案是:首先是深层副本，然后将引用传递给副本.

if you really want to, the answer is: first deep copy, then pass a reference to the copy.

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