Get UITextField text as you type

uitextfield_validation.m

- (BOOL)textField:(UITextField *)textField shouldChangeCharactersInRange:(NSRange)range replacementString:(NSString *)string {
    NSMutableString* newText = [[NSMutableString alloc] init];
    [newText appendString:[textField.text substringWithRange:NSMakeRange(0, range.location)]];
    [newText appendString:string];
    NSLog(@"newText: %@", newText);    
}