oc 字典应用实例-成绩科目排序

 NSMutableArray *mutArray1 = [[NSMutableArray alloc]init];
        NSDictionary *dic = [[NSDictionary alloc]initWithObjectsAndKeys:[NSNumber numberWithInt:98],@"chinese", [NSNumber numberWithInt:68],@"math",[NSNumber numberWithInt:108],@"english",[NSNumber numberWithInt:58],@"politics",nil];
        NSArray *array = [dic allValues];
        NSLog(@"%@",array);
        array = [array sortedArrayUsingSelector:@selector(compare:)];
        NSLog(@"%@",array);
//        NSArray *array1 = [dic allKeysForObject:[NSNumber numberWithInt:98]];
//        NSString *str2 = [array1 objectAtIndex:0];
//        NSLog(@"%@",str2);
        for (int i = 0; i < array.count; i ++)
        {
            NSArray *array2 = [dic allKeysForObject:[array objectAtIndex:i]];//在排好序数组中按照值取键
            NSString *str2 = [array2 objectAtIndex:0];//在数组中把键取出
            [mutArray1 addObject:str2];//取出的键加到新的数组中
        }
        NSLog(@"mutArray2 = %@",mutArray1);
    }