1 //创建字典 2         NSMutableDictionary *mutableDic=[[NSMutableDictionary alloc] 3                                          initWithObjectsAndKeys:@"jay",@"name", 4                                                                 @"22",@"age", 5                                                                 @"f",@"gender", nil]; 6         NSLog(@"%@",mutableDic); 7         //创建空的字典 8         NSMutableDictionary *mutab=[NSMutableDictionary dictionary]; 9         //将字典mutableDic复制到mutab中10         [mutab setDictionary:mutableDic];

 

//添加键值对的方式（向字典内添加一组键值）        NSDictionary *dict1=[NSDictionary dictionaryWithObject:@"166" forKey:@"height"];        [mutableDic addEntriesFromDictionary:dict1];        NSLog(@"%@",mutableDic);        //直接添加方式如果key存在时，就是修改对应的value值，如果不存在则是添加        [mutableDic setValue:@"66" forKey:@"weight"];        NSLog(@"%@",mutableDic);

1 //将字典中对应key的值删除2         [mutableDic removeObjectForKey:@"weight"];3         //删除一组key对应的value值4         [mutableDic removeObjectsForKeys:@[@"height",@"age"]];5         //删除所有value值6         [mutableDic removeAllObjects];

1 //遍历 2         //(1) 1.先找到所有key 2.计算key的个数，用来循环 3.通过key的数组找到对应key的值 (这种方法较慢) 3         NSArray *keyss=[mutableDic allKeys]; 4         NSUInteger count=[mutableDic count]; 5         for(int i=0;i