I want to create a Regular Expression which will only the input string to contain only [G|y|M|d|D|F|E|h|H|m|s|S|w|W|a|z|Z] so I come up with some code from below:
std::regex Reg = regex("[G|y|M|d|D|F|E|h|H|m|s|S|w|W|a|z|Z]");
My problem is that my regex still not correct because my input string can contain other characters with the characters in the above group such as:
std::string myInputString = Gx //correct
Which Gx has to be wrong
I’m not a user of C++’s regex lib, but I understand it supports ECMAScript syntax. So I don’t think you need the pipe characters. The “any character in set” [] syntax doesn’t use pipes. Secondly, if you want to match the entire input string (instead of any part of it) you need to use the ^ and $ anchors
Try:
std::regex( "^[GyMdDFEhHmsSwWazZ]+$" );
| character within the square-brackets then it will match it, so if the input string is "Z|a" then that will be treated as valid. I don't think that's what you want.What i can understand from your question is that, you want to input string with those chosen characters only
the regex is correct up to my knowledge
but you need to compare the string char by char because if you are not doing that you might get the similar results like you are getting now...
std::regex regex("^[G|y|M|d|D|F|E|h|H|m|s|S|w|W|a|z|Z| |?]+$"); and then use regex_match It will worked.