

Task

   match a string against a regular expression
   substitute part of a string using a regular expression


NSString *str = @"I am a string";
NSString *regex = @".*string$";
 
// Note: the MATCHES operator matches the entire string, necessitating the ".*"
NSPredicate *pred = [NSPredicate predicateWithFormat:@"SELF MATCHES %@", regex];
 
if ([pred evaluateWithObject:str]) {
    NSLog(@"ends with 'string'");
}