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JavaScript

Posted by Caleb Newell
Caleb Newell
12,562 Points

My code is not adding or removing list elements

I can't seem to figure out what is wrong with my code. When you push add list button, it is supposed to add a element to the ul. Does anyone see what is wrong?

JavaScript:

const toggleList = document.getElementById('toggleList');
const listDiv = document.querySelector('.list');
const descriptionInput = document.querySelector('input.description');
const descriptionP = document.querySelector('p.description');
const descriptionButton = document.querySelector('button.description');
const addItem = document.querySelector('input.addItem');
const addItemButton = document.querySelector('button.addItemButton');
const removeItemButton = document.querySelector('button.removeItemButton');

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

descriptionButton.addEventListener('click', () => {
  descriptionP.innerHTML = descriptionInput.value + ':';
  descriptionInput.value = '';
});

removeItemButton.addEventListener('click', () => {
  let ul = document.getElementsByTagName('ul')[0];
  let li = document.querySelector('li:last-child');
  ul.removeChild('li');
});

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 type='text' 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>
        <input type='text' class='adItemInput'>
        <button class='addItemButton'>Add item</button>
        <button class='removeItemButton'>Remove last item</button>
      </div>   
    <script src="app.js"></script>
  </body>
</html>

1 Answer

Simon Coates
Simon Coates
8,223 Points
Simon Coates
Simon Coates
8,223 Points

Should the following line use == or ===?

   if (listDiv.style.display = 'none') {

And you should probably remove the quotation marks on the removeChild method

  ul.removeChild(li); //rather than ul.removeChild('li');
Caleb Newell
Caleb Newell
12,562 Points

here is the working code

const toggleList = document.getElementById('toggleList');
const listDiv = document.querySelector('.list');
const descriptionInput = document.querySelector('input.description');
const descriptionP = document.querySelector('p.description');
const descriptionButton = document.querySelector('button.description');
const addItem = document.querySelector('input.addItem');
const addItemButton = document.querySelector('button.addItemButton');
const removeItemButton = document.querySelector('button.removeItemButton');

const addItemInput = document.querySelector('input.addItemInput');

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

descriptionButton.addEventListener('click', () => {
  descriptionP.innerHTML = descriptionInput.value + ':';
  descriptionInput.value = '';
});

addItemButton.addEventListener('click', () => {
  let ul = document.getElementsByTagName('ul')[0];
  let li = document.createElement('li');
  li.textContent = addItemInput.value;
  ul.appendChild(li);
  addItemInput.value = '';
});

removeItemButton.addEventListener('click', () => {
  let ul = document.getElementsByTagName('ul')[0];
  let li = document.querySelector('li:last-child');
  ul.removeChild(li);
});

<!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 type='text' 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>
        <input type='text' class='addItemInput'>
        <button class='addItemButton'>Add item</button>
        <button class='removeItemButton'>Remove last item</button>
      </div>   
    <script src="app.js"></script>
  </body>
</html>