How do I sort an NSMutableArray with custom objects in it?

Question

What I want to do seems pretty simple, but I can\'t find any answers on the web. I have an NSMutableArray of objects, and let\'s say they are \'Person\' objects

Answer 1

Starting in iOS 4 you can also use blocks for sorting.

For this particular example I'm assuming that the objects in your array have a 'position' method, which returns an NSInteger.

NSArray *arrayToSort = where ever you get the array from... ;
NSComparisonResult (^sortBlock)(id, id) = ^(id obj1, id obj2) 
{
    if ([obj1 position] > [obj2 position]) 
    { 
        return (NSComparisonResult)NSOrderedDescending;
    }
    if ([obj1 position] < [obj2 position]) 
    {
        return (NSComparisonResult)NSOrderedAscending;
    }
    return (NSComparisonResult)NSOrderedSame;
};
NSArray *sorted = [arrayToSort sortedArrayUsingComparator:sortBlock];

Note: the "sorted" array will be autoreleased.