通过文献传递对象 [英] passing in object by ref

问题描述

public function Foo(ref Bar bar)
{
   bar.Prop = 1;
}

public function Foo(Bar bar)
{
   bar.Prop = 1;
}

基本上什么是REF的点。是不是对象总是通过引用？

essentially what is the point of "ref". isn't an object always by reference?

推荐答案

的一点是，你永远不会真正传递的对象的。您传递的引用的 - 和参数本身可以通过引用或值传递。他们不同的表现，如果你改变参数值本身，例如：将其设置为空或不同的参考。随着 REF 这种变化会影响调用者的变量;没有 REF 这只是一个的复制的被传递的价​​值，所以调用者没有看到任何改变的变量。

The point is that you never actually pass an object. You pass a reference - and the argument itself can be passed by reference or value. They behave differently if you change the parameter value itself, e.g. setting it to null or to a different reference. With ref this change affects the caller's variable; without ref it was only a copy of the value which was passed, so the caller doesn't see any change to their variable.

请参阅我的论点的文章传递更多细节。

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