Returns a reference to the last child element of the current element.
Note: The lastElementChild property is supported in Firefox from version 3.5 and Internet Explorer from version 9.
The last child node and the last child element can be different.
A node is an element node if it's nodeType is 1 (Node.ELEMENT_NODE).
Text nodes and comment nodes are not element nodes.
If you need the last child node of an element, use the lastChild property.
The children collection contains all child elements of an element in source order.
Since the children collection is supported widely by browsers, so you can use the last item from the children collection instead of the lastElementChild property.
Note: The children collection also contains the child comment nodes in Internet Explorer before version 9.
In other browsers, it only contains the element nodes.