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

Posted by nathang
.a{fill-rule:evenodd;}techdegree
nathang
Full Stack JavaScript Techdegree Student 12,035 Points

Hello, I am struggling with the portion of adding the class name to the <p> element. I have tried various methods.

I have tried various methods of adding a class and none of them seem to be what the challenge is looking for. I have also tried innerHTML as an option with no luck. Maybe I am not understanding what the challenge is asking for? Any guidance is greatly appreciated!

Thank you!

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

list.addEventListener('click', function(e) {
  if (e.target.tagName == 'BUTTON') {
    let li = e.target.parentNode;
    let prevLi = li.previousElementSibling;
    if(prevLi){
      prevLi.insertAdjacentHTML('beforebegin', "<p class = 'highlighted'></p>");
      prevLi.className = 'highlight';
    }
    if(!prevLi){
      li.nextElementSibling.nextElementSibling.nextElementSibling.insertAdjacentHTML('beforeBegin' , "<p class = 'highlighted'></p>"); 
      li.nextElementSibling.nextElementSibling.nextElementSibling.className= 'highligh';
    }
  }
});
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>
Ashish Mehra
Ashish Mehra
2,411 Points

Hi Nathan Gallegos ,

In the above code problem you already have target and you just need to get previous sibling of that target & add classname to it.

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

list.addEventListener('click', function(e) {
  if (e.target.tagName == 'BUTTON') {
    const para = e.target.previousSibling;
    if(para) para.className = "highlight";
  }
});

Hope it helps,

1 Answer

nathang
seal-mask
.a{fill-rule:evenodd;}techdegree
nathang
Full Stack JavaScript Techdegree Student 12,035 Points
nathang
.a{fill-rule:evenodd;}techdegree
nathang
Full Stack JavaScript Techdegree Student 12,035 Points

Thank you for your help Ashish! I really appreciate it!

Nathan