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
410 views
in Technique[技术] by (71.8m points)

c++ - Unsigned int reverse iteration with for loops

I want the iterator variable in a for loop to reverse iterate to 0 as an unsigned int, and I cannot think of a similar comparison to i > -1, as you would do if it was a signed int.

for (unsigned int i = 10; i <= 10; --i) { ... }

But this seems very unclear, as it is relying on the numerical overflow of the unsigned integer to be above 10.

Maybe I just don't have a clear head, but whats a better way to do this...

Disclaimer: this is just a simple use case, the upper limit of 10 is trivial, it could be anything, and i must be an unsigned int.

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)

You can use

for( unsigned int j = n; j-- > 0; ) { /*...*/ }

It iterates from n-1 down to 0.


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

...