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JavaScript

Posted by Abubakr Alhaj
Abubakr Alhaj
4,297 Points

Why both of the click event handlers, are firing?

Hi guys, Guil tried to explain why both event are firing and it erased the list description paragraph at the end, I couldn't understand how is that possible because both the querySelector() have different names.

HTML

<!DOCTYPE html>
<html>
  <head>
    <title>JavaScript and the DOM</title>
    <link rel="stylesheet" href="css/style.css">
  </head>
  <body>
    <h1 id="myHeading">JavaScript and the DOM</h1>
    <p>Making a web page interactive</p>
    <button id="toggleList">Hide list</button>
    <div class="list">
      <p class="description">Things that are purple:</p>
      <input type="text" class="description">
      <button class="description">Change list description</button>
      <ul>
        <li>grapes</li>
        <li>amethyst</li>
        <li>lavender</li>
        <li>plums</li>
      </ul>
    </div>
    <script src="app.js"></script>
  </body>
</html>

JavaScript code

const toggleList = document.getElementById('toggleList');
const listDiv = document.querySelector('.list');
const input = document.querySelector('input');
const p = document.querySelector('p.description');
const button = document.querySelector('button');

toggleList.addEventListener ('click', () => {
  if (listDiv.style.display == 'none') {
    toggleList.textContent = 'Hide list';
    listDiv.style.display = 'block';
  } else {
  toggleList.textContent = 'Show list';
  listDiv.style.display = 'none';
  }
});

button.addEventListener( 'click', () => {
  p.textContent = input.value + ':';
});

1 Answer

Hyrum Steffensen
Hyrum Steffensen
1,822 Points
Hyrum Steffensen
Hyrum Steffensen
1,822 Points 
const toggleList = document.getElementById('toggleList');

gets you the element:

<button id="toggleList">Hide list</button>

However, in the following line, querySelector returns the first button tag in the page, which returns the same element.

const button = document.querySelector('button');