返回类型指针是否与“更新类型”相同？ 在C＃中

Question

Instead of...

Video v = new Video();

I want to do

Video v = GetVideo();

public Video GetVideo()
{
   return new Video();
}

Are these two calls totally equal?

Answer 1

Yes, they are. I have used this approach several times to return me an object prepopulated by some default testing values.

Answer 2

Is returning a type pointer the same as 'newing a type'?

It depends on the method returning the object reference.

Your given snippets, for example, are functionally equivalent because GetVideo() does nothing except return a new Video() .

Answer 3

至少您可以将它们视为相等，如果它们位于相同的程序集中，则它们可能会内联到相同的IL代码。

Answer 4

They're the same in this case because the method also creates a new Video . However, consider this instead:

private Video video;

public Video GetVideo()
{
   if (video == null)
   {
       video = new Video();
   }
   return video;
}

Now a new Video object will be created only the first call - subsequent calls will return a reference to the existing object.

(That's only a simple example, of course - it could sometimes create a new one, sometimes not, sometimes return null etc.)