Welcome to the Treehouse Community

Want to collaborate on code errors? Have bugs you need feedback on? Looking for an extra set of eyes on your latest project? Get support with fellow developers, designers, and programmers of all backgrounds and skill levels here with the Treehouse Community! While you're at it, check out some resources Treehouse students have shared here.

Looking to learn something new?

Treehouse offers a seven day free trial for new students. Get access to thousands of hours of content and join thousands of Treehouse students and alumni in the community today.

Start your free trial

JavaScript JavaScript and the DOM (Retiring) Traversing the DOM Solution: Using nextElementSibling

Posted by Kat Stacy
Kat Stacy
41,658 Points

The down button is not working.

I used all of the same code the teacher used but my down button is not working. Help please!

listUl.addEventListener('click', (event) => {
  if (event.target.tagName == 'BUTTON') { 
    if (event.target.className == 'remove') {
      let li = event.target.parentNode;
      let ul = li.parentNode;
      ul.removeChild(li);
    }
    if (event.target.className == 'up') {
      let li = event.target.parentNode;
      let prevLi = li.previousElementSibling;
      let ul = li.parentNode;
      if (prevLi) {
        ul.insertBefore(li, prevLi);
      }
    }
    if (event.target.className == 'down') {
      let li = event.target.parentNode;
      let nextLi = li.nextElementSibling;
      let ul = li.parentNode;
      if (nextLi) {
        ul.insertBefore(nextLi, li);
      }
    }
  }
});

1 Answer

Joel Bardsley
Joel Bardsley
31,249 Points
Joel Bardsley
Joel Bardsley
31,249 Points

Hi Kat, you're very close and you'll probably kick yourself, but if you look at the documentation for the insertBefore() method, you'll find the following:

var insertedNode = parentNode.insertBefore(newNode, referenceNode);

For the 'up' button, you'll notice that prevLi was used as the referenceNode. Hopefully you'll now be able to see where you've gone wrong on the 'down' button!

Kat Stacy
Kat Stacy
41,658 Points

Thank you Joel. I was able to figure it out. There was a problem with the HTML.