Hi guys,
I've spent some time, but still have to solution. I need regular expression that is able to match a words with signs in it (like c++) in string.
I've used /\bword\b/, for "usual" words, it works OK. But as soon as I try /\bC\+\+\b/ it just does not work. It some how works wrong with a plus signs in it.
I need a regex to detect if input string contains c++ word in it. Input like,
"c++ developer"
"using c++ language"
etc.
ps. Using C#, .Net Regex.Match function.
Thanks for help!
+ is a special character so you need to escape it
\bC\+\+(?!\w)
Note that we can't use \b because + is not a word-character.
Plus sign have special meaning so you will have to escape it with \. The same rule applies to these characters: \, *, +, ?, |, {, [, (,), ^, $,., #, and white space
UPDATE: the problem was with \b sequence
The problem isn't with the plus character, that you've escaped correctly, but the \b sequence. It indicates a word boundary, which is a point between a word character (alphanumeric) and something else. Plus isn't a word character, so for \b to match, there would need to be a word character directly after the last plus sign.
\bC\+\+\b matches "Test C++Test" but not "Test C++ Test" for example. Try something like \bC\+\+\s if you expect there to be a whitespace after the last plus sign.
As the others said, your problem isn't the + sign you've escaped correctly but the \b that is a zero-lenght char that match word boundary that takes place between word \w and non-word \W char.
There is also another mistake in your regex, you want to match char C (uppercase) with c++ (lowercase).To do so you have to change your regex to /\bc\+\+/ or use the i modifier to match case insensitive : /\bc\+\+/i