Get the last item from node list without using .length

Question

The following command

document.querySelectorAll('#divConfirm table')[1].querySelectorAll('tr')

gives a node list with 3 tablerow (tr) elements in it. If I know the list size, I can access the last element via.item(2).

Is there a way to get the last element directly without resorting to .length first?

Answer 1

There's at least one way

var els = document.querySelectorAll('#divConfirm table')[1].querySelectorAll('tr');

var last = [].slice.call(els).pop();

but, the following statement

But if I do not know the length prior to running the script

makes no sense, you already have the collection of elements, so you would always know the length

var els = document.querySelectorAll('#divConfirm table')[1].querySelectorAll('tr');

var last = els[els.length - 1];

Another option would be

document.querySelector('#divConfirm table:nth-child(2) tr:last-child');