////  SportProtocol.h//  day17#import 
     
      @protocol SportProtocol 
      
       // 方法声明列表- (void)playFootball;- (void)playBasketball;- (void)playBaseball;@end
      
     

////  Person.h//  day17#import 
     
      #import "SportProtocol.h"  //相当于拷贝了一份方法的声明@interface Person : NSObject 
      
         //继承了协议，就有了协议里面所有方法的声明。继承实类默认就有实现，继承协议没有实现，@end
      
     

////  Person.m//  day17#import "Person.h"@implementation Person- (void)playFootball{    NSLog(@"%s", __func__);}- (void)playBasketball{    NSLog(@"%s", __func__);}- (void)playBaseball{    NSLog(@"%s", __func__);}@end

////  main.m//  day17#import 
     
      #import "Person.h"#import "Student.h"#import "Teacher.h"int main(int argc, const char * argv[]) {    Person *p = [Person new];    [p playFootball];    [p playBasketball];    [p playBaseball];        Student *stu = [Student new];    [stu playBaseball];            Teacher *tea = [Teacher new];    [tea playBasketball];        return 0;}