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

Mickey Odunikan
Mickey Odunikan
7,392 Points
Posted by Mickey Odunikan
Mickey Odunikan
7,392 Points

I don't understand why the class of the p tag won't change with this code

Lost

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

list.addEventListener('click', function(e) {
  if (e.target.tagName == 'BUTTON') {
   let li = document.querySelector('p');
   p.classList.add("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

Antonio De Rose
Antonio De Rose
20,885 Points
Antonio De Rose
Antonio De Rose
20,885 Points 
const list = document.getElementsByTagName('ul')[0];

list.addEventListener('click', function(e) {
  if (e.target.tagName == 'BUTTON') {
   let li = document.querySelector('p'); //you have declared a variable, which you have not used.
   p.classList.add("highlight");//there are many p's which p are you targetting

//think of something like an event driven, when you click an event, with the use of 'e' 
//as the parameter for the function, you can make use of of many of the methods inside
//the e object, say for example in your case
//when you refer, just like e.target.tagName, you can make use of the 
//e.target.previousElementSibling, not finished here, to add the class
//I give you the homework for you to complete.
//this way, you do not have to worry which 'p' do you wanna target.

  }
});