back to the lesson

The sibling question

importance: 5
  1. Yes, true. The element elem.lastChild is always the last one, it has no nextSibling, so if there are children, then yes.
  2. No, wrong, because elem.children[0] is the first child among elements. But there may be non-element nodes before it. So previousSibling may be a text node.

Please note that for both cases if there are no children, then there will be an error. For instance, if elem.lastChild is null, we can’t access elem.lastChild.nextSibling.

If elem – is an arbitrary DOM element node…

  • Is it true that elem.lastChild.nextSibling is always null?
  • Is it true that elem.children[0].previousSibling is always null ?