使用 &在 PHP 中获取对象的引用是多余的吗？
在 PHP 中，所有对象变量实际上都是指向对象的指针（不是？），该语言隐式处理这个问题（对吗？），但我看到许多 php 代码在参数中指定引用，如下所示：
function someMethod(SomeClass& $obj)
{
//...
}
我也看到过这样的事情：
function add()
{
$object = new SomeClass;
self::$objects[] =& $object;
}
如果我错了，请纠正我，但这里不会有任何区别：
self::$objects[] =& new SomeClass
self::$objects[] = new SomeClass
我是对的吗？？？？？？
我测试的另一件事：
class SomeClass{}
$obj =& new SomeClass; // is in fact deprecated, doesn't work
$obj = new SomeClass;
$obj2 =& $obj; // works, but should also be deprecated!! No?
In PHP, all object-variables are actually pointers to objects (no?), the language handles this implicitly (right?), yet I see many php code specifying references in parameters such as this:
function someMethod(SomeClass& $obj)
{
//...
}
I've also seen things like this:
function add()
{
$object = new SomeClass;
self::$objects[] =& $object;
}
Correct me if I'm wrong, but there wouldn't be any difference here:
self::$objects[] =& new SomeClass
self::$objects[] = new SomeClass
Am I right??????
Another thing I tested:
class SomeClass{}
$obj =& new SomeClass; // is in fact deprecated, doesn't work
$obj = new SomeClass;
$obj2 =& $obj; // works, but should also be deprecated!! No?
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评论（3）
在 php5 中，是的，这是多余且毫无意义的。
In php5, yes, it is redundant and pointless.
据我所知，与引用相关的唯一已被弃用的是调用时传递引用（例如
somefunction(&$var);您的代码示例可能具有
& ;符号用于 PHP 4 兼容性。无论您是否使用&来处理 PHP 5 中的对象引用，都没有太大区别。当然有一个 略有不同（在 PHP 5 中按值传递引用与使用&按引用传递对象之间），但在大多数情况下，在 PHP 5 中运行时它不会影响您的代码。The only thing related to references that is deprecated as far as I know is call-time pass-by-reference (e.g.
somefunction(&$var);Your code samples likely have the
&symbol for PHP 4 compatibility. It doesn't make much of a difference whether you use&or not to work with object references in PHP 5. Granted there is a slight difference (between passing references by value in PHP 5, and using&to pass objects by reference), but in most cases it shouldn't affect your code when run in PHP 5.此页面可能对您有帮助：
http://www.php.net/manual/en/language.operators .assignment.php
new自动返回一个引用，因此您不再对新声明的对象使用= &。This page may be helpful to you:
http://www.php.net/manual/en/language.operators.assignment.php
newautomatically returns a reference, so you don't use the= &anymore with a newly declared object.