问题
I was looking at the escape sequences for characters in strings in c++ and I noticed there is an escape sequence for a question mark. Can someone tell me why this is? It just seems a little odd and I can't figure out what ? does in a string. Thanks.
回答1:
It's to keep a question mark from getting misinterpreted as part of a trigraph.
For example, in
"What??!"
The "??! would be interpreted as the | character. So, you have to escape the question marks as follows:
"What\?\?!"
Example complements of http://msdn.microsoft.com/en-us/library/bt0y4awe%28VS.80%29.aspx
来源：https://stackoverflow.com/questions/1586834/escape-sequence-for-in-c