how to uninstall unnecessary simulators in Xcode?

You can find and delete the simulators from the path /Library/Developer/CoreSimulator/Profiles/Runtimes. Restart Xcode in order to take effect.


You can delete a simulator from Xcode by navigation through Menu > Window > Devices > Simulators.


How to check the character is backspace (delete)

- (BOOL) textField:(UITextField *) textField
shouldChangeCharactersInRange:(NSRange) range
            replacementString:(NSString *) string
     if ([string length])
          if ([string characterAtIndex:0] == 10)
               NSLog(@"keyboard backspace pressed");
      return YES;

Blogged with the Flock Browser