Welcome to OGeek Q&A Community for programmer and developer-Open, Learning and Share
Welcome To Ask or Share your Answers For Others

Categories

0 votes
835 views
in Technique[技术] by (71.8m points)

c# - If yield return never occurs, is null returned?

The method returns IEnumerable via a yield return statement.

If the yield statement never occurs (it's inside conditional logic), will the method return null, or will it return an Enumerable with a count of 0?

See Question&Answers more detail:os

与恶龙缠斗过久,自身亦成为恶龙;凝视深渊过久,深渊将回以凝视…
Welcome To Ask or Share your Answers For Others

1 Reply

0 votes
by (71.8m points)

A valid IEnumerable that produces no values when you iterate through it.

Just think of it: You can store the IEnumerable generator in a variable - the code itself just gets executed when you actually iterate through the results. How could you execute the code if you had null? Or how did you know the function doesn't yield anything without running it.


与恶龙缠斗过久,自身亦成为恶龙;凝视深渊过久,深渊将回以凝视…
OGeek|极客中国-欢迎来到极客的世界,一个免费开放的程序员编程交流平台!开放,进步,分享!让技术改变生活,让极客改变未来! Welcome to OGeek Q&A Community for programmer and developer-Open, Learning and Share
Click Here to Ask a Question

...