jQuery - sort DIVs by className

Answer 1

You changed the requirements mid way ... just like a true client. Updated version with some comments attached. Just to confirm, there are two "configurable" variables at the front.

classPrefix: the "prefix" unique to the class used to determine sort order ('cat' in this case) listElementSelector: the jQuery selector used to obtain the list to sort.

function OrderDIV(position)
{
    var classPrefix = 'cat';
    var listElementSelector = '#list';

    // -- Decrement the position to make it 0 based
    position--;

    // -- Parses the "position" section from the given classes, and
    //    then the position at the specific index requested.
    var parsePosition = function(classes, pos) {
        // -- Split the "classes" into an array.
        var classList = classes.split(' ');

        // -- Determine which of the "classes" starts with the prefix we want.
        for( var i in classList )
        {
            if( classList[i].substr(0, classPrefix.length) == classPrefix )
            {
                // -- Strip out the positions section, and split it.
                var positions = classList[i].split('-')[1].split('.');

                // -- return the one position we want
                return positions[pos];
            }
        }

        // -- In the event that we don't find the class we're looking for ...
        return -1;
    }

    // -- Compares div A to div B, and returns an indicator of the order
    var funcSort = function(a, b) {
        // -- Use "parsePosition" to determine the sortable criteria from the classes.
       var compA = parsePosition($(a).attr('class'), position);
       var compB = parsePosition($(b).attr('class'), position);
       return (compA < compB) ? -1 : (compA > compB) ? 1 : 0;
    };

    // -- Select the list element.
    var list = $(listElementSelector);

    // -- Select the list items, and return them as an array.
    var listitems = list.children('div').get();

    // -- Sort the array using the "funcSort".
    listitems.sort(funcSort);

    // -- Go through each of the array entries, and "append" them to the list container
    //   (this moves them to the 'back' of the list)
    $.each(listitems, function(idx, itm) { list.append(itm); });
}