sort Apparel Sizes in objective-c

Question

I have an NSArray with values XS, S, M, L, XL, XXL in random order.

How would I go about sorting this properly in Objective-C?

I looked at this code for a starting point but I am having zero luck:

Sort a list by reference C#

Answer 1

If you create an ordered set to act as a "reference" order, you can then use the NSMutableSet method intersectSet: to create an ordered list from your array:

Edit David Rönnqvist just made a good point. Need to check for multiple instances of the same 'size'.

//This is my "reference" set, declared only once in my class
NSOrderedSet *reference = [NSOrderedSet orderedSetWithObjects:@"XS",@"S",@"M",@"L",@"XL", nil];

//This is the array I'm trying to sort, which may or may not contain all the sizes
NSArray *randomArray = [NSArray arrayWithObjects:@"XL", @"XS", @"M", @"XS", nil];

//Create a mutable ordered set from my reference
NSMutableOrderedSet *ordered = [NSMutableOrderedSet orderedSetWithOrderedSet:reference];

//Interset with the array
[ordered intersectSet:[NSSet setWithArray:randomArray]];

//Look for multiple instances of the same size
NSMutableArray *result = [NSMutableArray array];

for (NSString *sortedSize in ordered){

    for (NSString *randomSize in randomArray){
        if ([randomSize isEqualToString:sortedSize]){
            [result addObject:randomSize];
        }
    }
}

My result from the above was an array containing:

@"XS", @"XS", @"M", @"XL"

If you were going to create a method that did this, you could also compare the count of ordered to the array you were sorting, and if they were equal don't bother with the iteration.