Question

I’ve basically got a little function called findItem() that is supposed to be finding the elements I’m looking for based on custom data- attributes on the element.

In this case these are purely numerical eg. data-slide=1.

I’m a bit clueless as to how to match the value of each item’s data-slide to one that is contained within the other array.

Here is a more concrete example:

function findItem(count) {
    var collection = [];

    $.each(allMyLiItems, function(i, item) {

        if ( $(item).data('slide') == count ) { 
            collection.push(item);
        }

    });

    return $(collection);
}
findItem([1,3])

which does not work because count inside the if statement does not seem to match anything.

The page does contain 4 <li data-slide="{number}">… elements so 1,3 should return the first and third of those elements.

What am I doing wrong here?

Answer 1

Use jQuery.grep and jQuery.inArray:

function findItem(items) {
    return jQuery.grep($('li'), function(element, index) { 
       return jQuery.inArray($(element).data('slide'), items) != -1;
    });
}

Working example