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

enoch okyere
enoch okyere
4,681 Points
Posted by enoch okyere
enoch okyere
4,681 Points

I am confused about how to add the "highlight" class to the previous sibling p tag. Any help?

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

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

    if(e.target.tagName == 'P'){
      let prev = e.target.previousElementSibiling;
      prev.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

jb30
jb30
44,806 Points
jb30
jb30
44,806 Points 
  if (e.target.tagName == 'BUTTON') {

    if(e.target.tagName == 'P'){
      let prev = e.target.previousElementSibiling;
      prev.className = "highlight";
    }
  }

If the tagName of e.target is 'BUTTON', then its tagName is not 'P'. Try deleting if(e.target.tagName == 'P'){ and the corresponding } and correcting the spelling of previousElementSibling.