iphone - 首先按 'nearest distance' 对两个 NSMutableArrays 进行排序

Question

我有两个数组，都充满了像这样的 NSString 对象:

NSMutableArray *titles = [[NSMutableArray alloc] initWithObjects:@"Title1", @"Title2", @"Title3", @"Title4", @"Title5", nil];

NSMutableArray *distances = [[NSMutableArray alloc] initWithObjects:@"139.45", @"23.78", @"347.82", @"10.29", @"8.29", nil];

如何先按最近的距离对两个数组进行排序？

所以结果是这样的:

titles = @"Title5", @"Title4", @"Title2", @"Title1", @"Title3"
distances = @"8.29", @"10.29", @"23.78", @"139.45", @"347.82"

我知道 NSSortDescriptor 可以在这些情况下使用，但在查看文档后，我仍然不确定如何使用。

Answer 1

我会以这种方式对距离进行排序...

NSNumberFormatter *f = [[NSNumberFormatter alloc] init];
[f setNumberStyle:NSNumberFormatterDecimalStyle];

NSArray *sortedDistances = [listItem sortedArrayUsingComparator: ^(id a, id b) {
    NSNumber *aNum = [f numberFromString:a];
    NSNumber *bNum = [f numberFromString:b];
    return [aNum compare:bNum];
}];

我想不出一种特别快速的方法来对关联的标题进行排序，但这应该可行......

NSMutableArray *sortedTitles = [NSMutableArray array];
NSDictionary *distanceTitle = [NSDictionary dictionaryWithObjects:titles forKeys:distances];

for (NSString *distance in sortedDistances) {
    NSString *associatedTitle = [distanceTitle valueForKey:distance];
    [sortedTitles addObject:associatedTitle];
}