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

Martin Coutts
Martin Coutts
18,154 Points
Posted by Martin Coutts
Martin Coutts
18,154 Points

Altering class of previous item

Hi, really struggling to work out exactly what I need to do here. I know i can add the class name by getting the p element and using .className = 'highlight'; but I can't quite work out the steps to get to this point. Watched the video before about moving sibling items up a list but not sure all of the steps are relevant.

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

list.addEventListener('click', function(e) {
  if (e.target.tagName == 'BUTTON') {

  }
});
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>

1 Answer

Romain Gaget
Romain Gaget
24,449 Points
Romain Gaget
Romain Gaget
24,449 Points

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

list.addEventListener('click', function(e) { if (e.target.tagName === 'BUTTON') { if(e.target.textContent.toLowerCase() === 'highlight') { let p = e.target.previousElementSibling; p.classList.add('highlight'); } } });