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

Dan Warren
Dan Warren
9,125 Points
Posted by Dan Warren
Dan Warren
9,125 Points

Still need help solving this code challenge

I'm still having trouble with passing this challenge and have been at it for over a week now. Any help is appreciated.

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

list.addEventListener('click', function(e) {
  if (e.target.tagName == 'BUTTON') {
    let li = event.target.parentNode;
    let ul = li.parentNode;
    let prevLi = li.previousElementSibling;
    prevLi.style.backgroundColor = 'blue';
    let p = document.getElementsByTagName('p')[0];
    p.className += "highlight";
  }
});
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

Byron Injeeli
.a{fill-rule:evenodd;}techdegree seal-36
Byron Injeeli
Full Stack JavaScript Techdegree Graduate 25,639 Points

Hi Dan - your solution was very close, but the problem was that you were trying to target the previous <li></li> instead of the <p></p> element (it is a bit confusing in the challenge). See example below: 

<ul>
    <li>
        <p>DOM Traversal</p>
        <button>Highlight</button>
    </li>
</ul>

The goal of the challenge is that when a user clicks the Highlight button, the hightlight class should be added to the <p>DOM Traversal</p> element. You don't need to target the previous <li></li> element. The previousElementSibling of the button is the paragraph.

I'm adding the solution below, but feel free to try it out on your own first if you want.

if (e.target.tagName === 'BUTTON') {
    e.target.previousElementSibling.className = 'highlight';
}
Dan Warren
Dan Warren
9,125 Points
Dan Warren
Dan Warren
9,125 Points

Thanks! Can't believe I spent all that time declaring variables when all I needed was one line of code lol waaaaaaaaay simpler than what I was trying to do.