ios - 遍历 block 中的数组以对其成员进行排序

Question

如何在这样的 block 中获取 [index] 处的对象？它的目的是获取它的第一个字母并按字典顺序对 NSDictionaries 数组进行排序。

NSArray *sortedArray;
sortedArray = [_photos sortedArrayUsingComparator:^NSComparisonResult(id a, id b) {
    NSString *first = _photos[0][FLICKR_PHOTO_TITLE];
    NSString *second = _photos[0][FLICKR_PHOTO_TITLE];
    return [first compare:second];
}];
_photos = sortedArray;

Answer 1

看来您有一系列字典。要对 FLICKR_PHOTO_TITLE 键的值进行排序，您可以:

_photos = [_photos sortedArrayUsingComparator:^NSComparisonResult(NSDictionary *a, NSDictionary *b) {
    NSString *first = a[FLICKR_PHOTO_TITLE];
    NSString *second = b[FLICKR_PHOTO_TITLE];
    return [first compare:second];
}];