Objective-C 有关类和方法的判断处理

/*
- (BOOL)isKindOfClass:(Class)aClass 对象是否是某个类或其子类的成员
- (BOOL)isMemberOfClass:(Class)aClass 对象是否是类的成员
- (BOOL)respondsToSelector:(SEL)aSelector 对象能不能响应相关的函数
+ (BOOL)instancesRespondToSelector:(SEL)aSelector 指定的类实例能否响应相关的方法
*/
NSLog(@"%hhd",[roy isKindOfClass:[Person class]]); // 1
NSLog(@"%hhd",[teacher isMemberOfClass:[Teacher class]]); // 1
NSLog(@"%hhd",[roy respondsToSelector:@selector(setName: andAge:)]); // 1
NSLog(@"%hhd",[Person instancesRespondToSelector:@selector(setName: andAge:)]); // 1
NSLog(@"%hhd",[Teacher isSubclassOfClass:[Person class]]); // 1