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JavaScript JavaScript and the DOM (Retiring) Traversing the DOM Sibling Traversal

Ahmad Alshaar
Ahmad Alshaar
10,193 Points

I got stuck in this Code challenge.

Hello every one! i tried lots of ways to solve this challenge but i could not the question : Ahmad Alshaar I got stuck in this Code challenge.

complete the code to add a class "highlight " to "p " element that is the immediate sibling of the button being clicked

any ideas are so much appreciated Thank u guys!

app.js
var list = document.getElementsByTagName('ul')[0];

list.addEventListener('click', function(e) {
  if (e.target.tagName == 'BUTTON') {
 let x  = document.getElementsByTagName('p').previousElementSibling;

  }
});
index.html
<!DOCTYPE html>
<html>
    <head>
        <title>JavaScript and the DOM</title>
    </head>
    <link rel="stylesheet" href="style.css" />
    <body>
        <section>
            <h1>Making a Webpage Interactive</h1>
            <p>Things to Learn</p>
            <ul>
                <li><p>Element Selection</p><button>Highlight</button></li>
                <li><p>Events</p><button>Highlight</button></li>
                <li><p>Event Listening</p><button>Highlight</button></li>
                <li><p>DOM Traversal</p><button>Highlight</button></li>
            </ul>
        </section>
        <script src="app.js"></script>
    </body>
</html>

Hi, the challenge is asking you to select the previousElementSibling of each button in the variable list which is an unordered list.

You don't need to select a new p element, because you can select the previous siblings of all the buttons with selectPreviousSibling on the target of the event.

You also need to add a highlight class to the p element which you can do so like this:

e.target.previousElementSibling.classList.add('highlight');

:star:

1 Answer

HI Ahmad , When you click a highlight button the sibling, in this case, the paragraph <p></p> tag to have the class highlight. The class highlight has a CSS rule assigned to it.

const list = document.getElementsByTagName('ul')[0];

list.addEventListener('click', function(e) {
  if (e.target.tagName == 'BUTTON') {
    let li = e.target.previousSibling
    li.className = "highlight";
  }
});
Ahmad Alshaar
Ahmad Alshaar
10,193 Points

thank u very much it works