是"if(！myobject)"与"if(myobject == null)"相同吗? [英] Is "if(!myobject)" the same as "if(myobject == null)"?

问题描述

今天，我在Unity项目中遇到了一些有趣的C#代码:

Today I've come across an interesting bit of C# code in a Unity project:

MyScript ms = new MyScript(); //MyScript derives from MonoBehaviour
ms = null;
if(!ms) { Debug.Log("ms = "+(ms==null)); }

它的行为似乎与以下内容相同:

It does seem to behave the same as:

if(ms == null) { /*Do Stuff*/ }

但这真的是同一回事吗?我还没有找到关于此的任何文档.有没有理由不使用较短的版本，或者不喜欢使用另一个版本?

But is it really the same thing? I haven't found any documentation about this anywhere yet. Is there a reason to not use the shorter version or prefer one over the other?

推荐答案

否.您可以使用Javascript来实现，但是C#不能那样工作，除非myobject实际上是一个布尔值.

No. You can do that in Javascript, but C# doesn't work like that unless myobject is actually a boolean.

基于此评论:

myobject ...源自MonoBehaviour.

myobject ... derives from MonoBehaviour.

以及来自 MonoBehavior文档:

Operators

bool           Does the object exist?  
operator !=    Compares if two objects refer to a different object.  

您似乎可以对变量执行此操作，因为它可以隐式转换为bool.但是对于C#来说通常不行.

It looks like you can do this for your variable, becuase it is implicitly convertible to bool. But it's not generally okay for C#.

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