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

Samantha Atkinson
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Samantha Atkinson
Front End Web Development Techdegree Graduate 40,307 Points
Posted by Samantha Atkinson
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Samantha Atkinson
Front End Web Development Techdegree Graduate 40,307 Points

Which li item is actually moving? Is it the one next to the button you click?

When you create variables for:

let prevLi = li.previousElementSibling;
let nextLi = li.nextElementSibling;

<ul>
<li>amethyst 
          <button class="up">Up</button> 
          <button class="down">Down</button>             
          <button class="remove">Remove</button>
        </li>
        <li>lavender 
          <button class="up">Up</button>
          <button class="down">Down</button>              
          <button class="remove">Remove</button>
        </li>
        <li>plums 
          <button class="up">Up</button> 
          <button class="down">Down</button>             
          <button class="remove">Remove</button>
        </li>
      </ul>

So if I click the Down button on the amenthyst is it the li item lavender that is the actual element that moves because it's the nextElementSibling ?

1 Answer

Steven Parker
Steven Parker
231,275 Points
Steven Parker
Steven Parker
231,275 Points

You're exactly right. The move is performed by this line:

    ul.insertBefore(nextli, li);

So it's the next list item that gets moved, and placed in front of the one containing the button that was clicked.

Samantha Atkinson
seal-mask
.a{fill-rule:evenodd;}techdegree seal-36
Samantha Atkinson
Front End Web Development Techdegree Graduate 40,307 Points
Samantha Atkinson
.a{fill-rule:evenodd;}techdegree seal-36
Samantha Atkinson
Front End Web Development Techdegree Graduate 40,307 Points

Thank you, Steven, that clarifies my understanding of the nextElementSibling or previousElementSibling. I really didn't get it the first time. I am going to have a look over the code again with new understanding eyes : )