是通过值还是引用来完成多个变量分配? [英] Are multiple variable assignments done by value or reference?

问题描述

$a = $b = 0;

在上面的代码中，是否同时为$a和$b分配了0的值，还是$a仅引用了$b?

In the above code, are both $a and $b assigned the value of 0, or is $a just referencing $b?

推荐答案

使用原始类型，这是一个副本.

With raw types this is a copy.

test.php

$a = $b = 0;

$b = 3; 

var_dump($a);
var_dump($b);

输出:

int(0) 
int(3)

尽管有了对象，这是另一个故事(PHP 5)

With objects though, that is another story (PHP 5)

test.php

class Obj
{ 
    public $_name;
}

$a = $b = new Obj();

$b->_name = 'steve';

var_dump($a);
var_dump($b);

输出

object(Obj)#1 (1) { ["_name"]=> string(5) "steve" } 
object(Obj)#1 (1) { ["_name"]=> string(5) "steve" }

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