1 void dicUse() 2 { 3     NSMutableDictionary *dic = [NSMutableDictionary dictionary]; 4     Student *stu1 = [Student studentWithName:@"Simon"]; 5     6     NSLog(@"stu1:%zi", [stu1 retainCount]); 7     [dic setObject:stu1 forKey:@"k1"]; 8     NSLog(@"stu1:%zi", [stu1 retainCount]); 9    10     [dic setObject:[Student studentWithName:@"Joke"] forKey:@"k2"];11     NSLog(@"%@", dic);12    13     [dic removeObjectForKey:@"k1"];14     NSLog(@"after remove stu1:%zi", [stu1 retainCount]);15    16     NSMutableDictionary *dic2 = [NSMutableDictionary dictionary];17     [dic2 addEntriesFromDictionary:dic];18     NSLog(@"dic2: %@", dic2);19 }

1         NSMutableDictionary *d11_1 = @{@"姓名":@"张三", @"年龄":@"21", @"性别":@"男"};