iOS如何对包含字典的数组进行排序

Question

我有一个NSMutablearray，由字典组成 [来自JSON请求]

我需要根据字典中的一个键整理这个数组

字典

IdReward = 198;
Name = "Online R d";
RewardImageUrl = "/FileStorimage=1206";
WinRewardPoints = 250;

所以这个数组由不同形式的字典组成，我需要按最大到最小的顺序组织WinRewardPoints

我在stackoverflow上看到了这个答案，但我还不明白如何将其应用到我的情况中，

非常感谢！

- manuelBetancurt

---

那个答案的哪一部分让你感到困惑了？那个答案是正确且非常简单的。 - rob mayoff

Answer 1

IdReward = 198;
Name = "Online R d";
RewardImageUrl = "/FileStorimage=1206";
WinRewardPoints = 250;


NSMutableArray *arr = [[NSMutableArray alloc]init];

for (int i=0; i<[dict count]; i++) {
    [arr addObject:[dict valueForKey:@"WinRewardPoints"]];
}

NSSortDescriptor *sortDescriptor = [[[NSSortDescriptor alloc] initWithKey:nil ascending:YES] autorelease];
NSArray *sortDescriptors = [NSArray arrayWithObject:sortDescriptor];
arr = [[arr sortedArrayUsingDescriptors:sortDescriptors] copy];


NSMutableArray *final_arr = [[NSMutableArray alloc]init];
for(NSString* str in arr)<p>
{
    for(int i=0 ; i<[dict count]; i++)
    {
            <t>if ([str isEqualToString:[[dict valueForKey:@"WinRewardPoints"]objectAtIndex:i]]) 
                            {

                [final_arr addObject:[dict objectAtIndex:i]];
            }
    }

}

NSLog(@"%@",final_arr);

- Sirji

Answer 2

// create a NSString constant for the key we want to sort by, so we don't have to create more NSString instances while sorting
static NSString* const keyToSortBy = @"WinRewardPoints";

// sort an array that contains dictionaries, each of which contains a NSNumber for the key defined "WinRewardPoints"
[yourArray sortUsingComparator:^NSComparisonResult(id obj1, id obj2) {
    NSNumber* n1 = [obj1 objectForKey:keyToSortBy];
    NSNumber* n2 = [obj2 objectForKey:keyToSortBy];
    return [n1 compare:n2];
}];

- Andreas Ley