stringByReplacingOccurrencesOfString Regular Expression - objective-c

Question

I'm developing a Mac app and I'm trying to replace use NSString's stringByReplacingOccurrencesOfString. I'm doing something like:
NSString *new = [s stringByReplacingOccurrencesOfString:#"(special-tag)*.*</body" withString:html];
On an NSString. But whenever I try to use this function with a regular expression it seems to break. Is there something I'm missing? I found a few external regex libraries, but I'd rather use something built in that has similar functionality.
Any advice? Thanks in advance! EDIT - I know why it's breaking, I need help figuring out how to do an NSString replace with regular expressions

Answer 1

As the name suggest stringByReplacingOccurrencesOfString OccurrencesOfString it's a string not a RegEx. So it will replace your string rather than your RegEx.
-----------Edited-----------------
I haven't used regex before hope this will give you the idea
NSString *string = #"this is your string";
NSError *error = NULL;
NSRegularExpression *regex = [NSRegularExpression regularExpressionWithPattern:#"\\b(a|b)(c|d)\\b" options:NSRegularExpressionCaseInsensitive error:&error];
NSString *modifiedString = [regex stringByReplacingMatchesInString:string options:0 range:NSMakeRange(0, [string length]) withTemplate:#"$2$1"];
Here is the NSRegularExpression Class Reference

Answer 2

Take a look at the NSRegularExpression class. It sounds like the -stringByReplacingMatchesInString:options:range:withTemplate: method will fit your needs. You might also like –replaceMatchesInString:options:range:withTemplate:.