Question

让我有未排序的 NSMutableDictionary

    {
        A = "3";
        B = "2"; 
        C = "4";
    }

我需要结果如下：

    {
        B = "2";
        A = "3";
        C = "4";
    }

如何在目标c 中实现此结果。

一个简单的代码实现将不胜感激。

Answer 1

NSMutableDictionary不可能，它不是排序结构。您将不得不将其转换为NSArray然后对其进行排序。那么你将没有字典结构。

Answer 2

您不能将值 NSMutableDictionary 排序为@joe和@mavrick3。但是，如果您将键和值更改为 NSArray ，则可以执行此操作。这是简单的实现.. NSMutableDictionary *结果; //要排序的字典

    NSMutableDictionary *results; //dict to be sorted
    NSArray *sortedKeys = [results keysSortedByValueUsingComparator: ^(id obj1, id obj2) {
        if ([obj1 integerValue] > [obj2 integerValue]) 
            return (NSComparisonResult)NSOrderedDescending;
        if ([obj1 integerValue] < [obj2 integerValue])
            return (NSComparisonResult)NSOrderedAscending; 
        return (NSComparisonResult)NSOrderedSame;
    }];
    NSArray *sortedValues = [[results allValues] sortedArrayUsingSelector:@selector(compare:)];

    //Descending order
    for (int s = ([sortedValues count]-1); s >= 0; s--) {
        NSLog(@" %@ = %@",[sortedKeys objectAtIndex:s],[sortedValues objectAtIndex:s]); 
    }
    //Ascending order
    for (int s = 0; s < [sortedValues count]; s++) {
        NSLog(@" %@ = %@",[sortedKeys objectAtIndex:s],[sortedValues objectAtIndex:s]); 
    }

Answer 3

您可以尝试按字母排序。

 NSMutableDictionary *tmpDict = [NSMutableDictionary dictionaryWithObjectsAndKeys:@"6",@"A",@"3",@"B",@"5",@"C",@"2",@"D",@"21",@"F",@"20",@"G",nil];


NSArray *sortedArray = [tmpDict keysSortedByValueUsingComparator:^NSComparisonResult(id obj1,id obj2){


    return [obj1 compare:obj2 options:NSNumericSearch];


}];

NSLog(@"Sorted = %@",sortedArray);

Answer 4

NSDictionary以及NSMutableDictionary无法按值排序。您只能使用NSArray对其进行排序。但是你必须使用自己的代码，并且你不会得到你想要的相同输出。

Answer 5

这是最简单的方法

NSArray *arr = [NSArray arrayWithObjects:@"2", @"4", @"1", nil];
NSArray *sorted = [arr sortedArrayUsingSelector:@selector(compare:)];
NSLog(@"Pre sort : %@", arr);
NSLog(@"After sort : %@", sorted);

如果你有f.ex.字典数组（或模型对象），你可以这样做：

NSDictionary *dict1 = [NSDictionary dictionaryWithObject:@"Mannie" forKey:@"name"];
NSDictionary *dict2 = [NSDictionary dictionaryWithObject:@"Zannie" forKey:@"name"];
NSDictionary *dict3 = [NSDictionary dictionaryWithObject:@"Cannie" forKey:@"name"];
NSArray *peopleIKnow = [NSArray arrayWithObjects:dict1, dict2, dict3, nil];

NSSortDescriptor *sorty = [NSSortDescriptor sortDescriptorWithKey:@"name" ascending:YES];

NSArray *results = [peopleIKnow sortedArrayUsingDescriptors:[NSArray arrayWithObject:sorty]];

NSLog(@"Before : %@", peopleIKnow);
NSLog(@"After : %@", results);

NSMutableDictionary无法正确排序

5 个答案: