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 Making Changes to the DOM Remove Nodes

Posted by Kade Rathbun
Kade Rathbun
6,586 Points

Display an error message when there are no more list elements to remove?

I was wondering a basic way to display an error message once all task items are removed from the list? I see the console throws an error once all items are removed, so how could display an alert for example? Thanks :)

1 Answer

Steven Parker
Steven Parker
231,269 Points
Steven Parker
Steven Parker
231,269 Points

When there are no more items, the querySelector returns null, and attempting to perform the remove on that causes the error. You can easily test the value from querySelector and either remove it or issue a message:

  const lastItem = document.querySelector("li:last-child");
  if (lastItem)
    lastItem.remove();        // it's not null, so remove it
  else
    alert("No more items!");  // otherwise alert