Object-C加強 SEL類型

    SEL sel = @selector(stringByAppendingString:);

    CZPerson *person = [[CZPerson alloc] init];

    CZDog *dog = [[CZDog alloc] init];

    [person makeObject:dog perfomWithSelector:@selector(show)];

    // (NSObject) 表示某個對象是否能響應一個方法,中點掌握的方法

    BOOL is = [dog respondsToSelector:@selector(show)];