以升序排列的数组中不失指数的Objective-C [英] Sorting an array in ascending order without losing the index Objective-C

问题描述

我有实例的阵列，

    Array {
    3.0 at Index 0
    2.0 at Index 1
    3.5 at Index 2
    1.0 at Index 4
}

我想排序得到它以升序没有摆在首位丢失索引，这样，

I would like to get sort it in ascending order without losing the index in the first place, like this,

    Array {
    1.0 at Index 4
    2.0 at Index 1
    3.0 at Index 0
    3.5 at Index 2
}

当我使用这个数组排序，

When I sort the array using this,

NSArray *sortedArray = [hArray sortedArrayUsingSelector:@selector(caseInsensitiveCompare:)];
[knnRecog sortUsingDescriptors:[NSArray arrayWithObject:sortAsc]];

我失去了指数。有谁知道一种方法preserve排序后数组的索引？谢谢

I lose the index. Does anyone know a way to preserve the index after sorting the array? Thanks

推荐答案

您可以做你需要与更改您的基础数据结构排序。考虑使用数组的数组，例如：

You can do the sorting you require with a change to your underlying data structure. Consider using an array of arrays, e.g.:

{
    {3.0, Index 0},
    {2.0, Index 1},
    {3.5, Index 2},
    {1.0, Index 4}
}

和给定分选功能：

NSComparisonResult customCompareFunction(NSArray* first, NSArray* second, void* context)
{
    id firstValue = [first objectAtIndex:0];
    id secondValue = [second objectAtIndex:0];
    return [firstValue compare:secondValue];
}

您可以像这样排序是：

NSArray* myArray = [NSArray arrayWithObjects:
                    [NSArray arrayWithObjects:
                     [NSNumber numberWithFloat:3.0f],
                     [NSNumber numberWithInt:0], nil],
                    [NSArray arrayWithObjects:
                     [NSNumber numberWithFloat:2.0f],
                     [NSNumber numberWithInt:1], nil],
                    [NSArray arrayWithObjects:
                     [NSNumber numberWithFloat:3.5f],
                     [NSNumber numberWithInt:2], nil],
                    [NSArray arrayWithObjects:
                     [NSNumber numberWithFloat:1.0f],
                     [NSNumber numberWithInt:4], nil]];

NSArray* sortedArray = [myArray sortedArrayUsingFunction:customCompareFunction context:NULL];

NSLog(@"Sorted array: %@", sortedArray);

它打印：

排序数组：（
        （
        1，
        4
    ）
        （
        2，
        1
    ）
        （
        3，
        0
    ）
        （
        3.5，
        2
    ）
）

Sorted array: ( ( 1, 4 ), ( 2, 1 ), ( 3, 0 ), ( 3.5, 2 ) )

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