在objective c中按日期、月和年对日期数组进行排序

NSComparator dateComparator = ^(NSDate *date1, NSDate *date2) {
    return [date1 compare:date2];
};

// 假设dates是一个包含NSDate对象的日期数组
NSArray *sortedDates = [dates sortedArrayUsingComparator:dateComparator];

// 按月份排序
NSSortDescriptor *monthSortDescriptor = [NSSortDescriptor sortDescriptorWithKey:@"self" ascending:YES];
NSArray *sortedDatesByMonth = [dates sortedArrayUsingDescriptors:@[monthSortDescriptor]];

// 按年份排序
NSSortDescriptor *yearSortDescriptor = [NSSortDescriptor sortDescriptorWithKey:@"self" ascending:YES];
NSArray *sortedDatesByYear = [dates sortedArrayUsingDescriptors:@[yearSortDescriptor]];