Sorting NSString values as if NSInteger using NSSortDescriptor

Question

I have created a sort descriptor to sort a plist response coming from my server. This works well with sort key having values upto 9. With more than 10 items I see abrupt res

Answer 1

You need your strings to be compared with the NSNumericSearch option:

NSNumericSearch
Numbers within strings are compared using numeric value, that is, Name2.txt < Name7.txt < Name25.txt.

which requires the compare:options: method to be called for the comparison.

In order to do that, your sort descriptor can use an NSComparator Block:

[NSSortDescriptor sortDescriptorWithKey:@"self"
                              ascending:YES
                             comparator:^(NSString * string1, NSString * string2){
                                            return [string1 compare:string2
                                                            options:NSNumericSearch];
 }];

Or, indeed, you can skip the sort descriptor and simply sort the array directly, using the same Block:

[unsortedList sortedArrayUsingComparator:^NSComparisonResult (NSString * string1, NSString * string2){
    return [string1 compare:string2
                    options:NSNumericSearch];
 }];