[objective C] 判斷字串是否含有某些字串

NSString *string = @"hello bla bla";
if ([string rangeOfString:@"bla"].location == NSNotFound) {
  NSLog(@"string does not contain bla");
} else {
  NSLog(@"string contains bla!");
}

或是
if ([string rangeOfString:@"bla"].location != NSNotFound)

NSLog(@"string contains bla!");