[OC Foundation框架

 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 }

NSMutableDictionary不允许使用简化的集中初始化方法创建

error:

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