How to remove text within parentheses using NSRegularExpression?

Question

I try to remove part of the string which is inside parentheses.

As an example, for the string "(This should be removed) and only this part should remain" , after using NSRegularExpression it should become "and only this part should remain" .

I have this code, but nothing happens. I have tested my regex code with RegExr.com and it works correctly. I would appreciate any help.

NSString *phraseLabelWithBrackets = @"(test text) 1 2 3 text test";
NSError *error = NULL;
NSRegularExpression *regexp = [NSRegularExpression regularExpressionWithPattern:@"/\\(([^\\)]+)\\)/g" options:NSRegularExpressionCaseInsensitive error:&error];
NSString *phraseLabelWithoutBrackets = [regexp stringByReplacingMatchesInString:phraseLabelWithBrackets options:0 range:NSMakeRange(0, [phraseLabelWithBrackets length]) withTemplate:@""];
NSLog(phraseLabelWithoutBrackets);

Answer 1

Remove the regex delimiters and make sure you also exclude ( in the character class:

NSString *phraseLabelWithBrackets = @"(test text) 1 2 3 text test";
NSError *error = NULL;
NSRegularExpression *regexp = [NSRegularExpression regularExpressionWithPattern:@"\\([^()]+\\)" options:NSRegularExpressionCaseInsensitive error:&error];
NSString *phraseLabelWithoutBrackets = [regexp stringByReplacingMatchesInString:phraseLabelWithBrackets options:0 range:NSMakeRange(0, [phraseLabelWithBrackets length]) withTemplate:@""];
NSLog(phraseLabelWithoutBrackets);

See this IDEONE demo and a regex demo .

The \\([^()]+\\) pattern will match

• \\( - an open parenthesis
• [^()]+ - 1 or more characters other than ( and ) (change + to * to also match and remove empty parentheses () )
• \\) - a closing parenthesis