how to sort the time in a NSMutableArray in ios

问题

i'm having a set of Dictionaries in a NSMutableArray. now i want to sort ascending & Descending order by time here is my Array value.

(
    {
    StartTime = "09:00 AM";
    TravelsName = "ABC Travels";
},
    {
    StartTime = "07:30 AM";
    TravelsName = "XYZ Travels ";
},
    {
    StartTime = "06:45 PM";
    TravelsName = "GSP  Travels";
},
    {
    StartTime = "05:00 PM";
    TravelsName = "Madura  Travels";
},
    {
    StartTime = "12:45 AM";
    TravelsName = "MJT Travels";
},
    {
    StartTime = "12:45 PM";
    TravelsName = "OPR Travels";
},
    {
    StartTime = "01:00 AM";
    TravelsName = "VMS Travels";
}
)

Please help me i had sorted the set of NSDate inside the NSMutableArray by the below code

//To sort the Time Array
dateFormatter = [[NSDateFormatter alloc] init];
    [dateFormatter setDateFormat:@"hh:mm a"];

    NSMutableArray *dates = [NSMutableArray arrayWithCapacity:times.count];

    for (NSString *timeString in times)
    {
        NSDate *date = [dateFormatter dateFromString:timeString];
        [dates addObject:date];
    }
    [dates sortUsingSelector:@selector(compare:)];

    NSMutableArray *sortedTimes = [NSMutableArray arrayWithCapacity:dates.count];
    for (NSDate *date in dates)
    {
        NSString *timeString = [dateFormatter stringFromDate:date];
        [sortedTimes addObject:timeString];
    }

but i don't know how to sort the Dictionary in the NSMutableArray help me.

回答1:

It is best to use the sorting methods that are already provided in NSArray. Something like this should do:

NSArray *stortedArray = [unsortedArray sortedArrayUsingComparator:^NSComparisonResult(NSDictionary *_Nonnull obj1, NSDictionary *_Nonnull obj2) {
        return [obj1[@"StartTime"] compare:obj2[@"StartTime"]];
}];

Or if the StartTime is still a string:

NSArray *stortedArray = [unsortedArray sortedArrayUsingComparator:^NSComparisonResult(NSDictionary *_Nonnull obj1, NSDictionary *_Nonnull obj2) {
    return [[dateFormatter dateFromString:obj1[@"StartTime"]] compare:[dateFormatter dateFromString:obj2[@"StartTime"]]];
}];

To change the ascending/descending order you simply swap the obj1 and obj2 when used in the block:

return [obj2[@"StartTime"] compare:obj1[@"StartTime"]];

来源：https://stackoverflow.com/questions/33779272/how-to-sort-the-time-in-a-nsmutablearray-in-ios

标签

ios

objective-c

sorting

nsmutablearray

nsmutabledictionary