Question

I have an NSArray which contains some NSString objects. For example:

NSArray *objects = @[@"Stin",@"Foo",@"Ray",@"Space"];

Now I need to sort this array based on following order of Strings.

NSArray *sortOrder = @[@"John",@"Foo",@"Space",@"Star",@"Ray",@"Stin"];

So the answer should be

NSArray *sorted = @[@"Foo",@"Space",@"Ray",@"Stin"];

How can I achieve this?

ANSWER:
Based on Accepted answer of dasblinkenlight, I did following and it worked to charm.

NSMutableArray *objects = @[@"Star",@"Stin",@"Foo",@"Ray",@"Space",@"John"];
NSArray *sortOrder = @[@"John",@"Foo",@"Space",@"Star",@"Ray",@"Stin"];

[objects sortUsingComparator:^NSComparisonResult(id obj1, id obj2) {
    int index1 = [sortOrder indexOfObject:obj1];
    int index2 = [sortOrder indexOfObject:obj2];

    if (index1 > index2)
        return NSOrderedDescending;
    if (index1 < index2)
        return NSOrderedAscending;
    return NSOrderedSame;
}];

Answer 1

Create NSComparator that holds a reference to the superset array, and decides the relative order of strings by comparing the results of calling [superset indexOfObject:str] on both strings. Call sortedArrayUsingComparator: passing an instance of NSComparator to get the desired ordering.