JavaScript Dropdown menu - Interactive program

Last update on April 17 2024 13:04:01 (UTC/GMT +8 hours)

JavaScript Event Handling: Exercise-2 with Solution

Write a JavaScript program to create a dropdown menu that shows and hides its options when clicked.

Sample Solution:

HTML and JavaScript Code:

 <!DOCTYPE html>
<html>
<head>
  <style>
    .dropdown {
      position: relative;
      display: inline-block;
    }
    .dropdown-button {
      background-color:#7FFFD4;
      color: #333;
      padding: 10px;
      border: none;
      cursor: pointer;
    }
    .dropdown-options {
      display: none;
      position: absolute;
      background-color: #CC56FF;
      min-width: 120px;
      box-shadow: 0px 8px 16px 0px rgba(0,0,0,0.2);
      padding: 0;
      margin: 0;
      list-style: none;
      z-index: 1;
    }
    .dropdown-option {
      padding: 10px;
      cursor: pointer;
      border-bottom: 1px solid #ccc;
    }
    .dropdown-option:last-child {
      border-bottom: none;
    }
  </style>
</head>
<body>
  <div class="dropdown">
    <button class="dropdown-button">Select a Subject</button>
    <ul id="dropdown-options" class="dropdown-options">
      <li class="dropdown-option">Mathematics</li>
      <li class="dropdown-option">English</li>
      <li class="dropdown-option">Physics</li>
    </ul>
  </div>
  <script>
    const dropdownButton = document.querySelector('.dropdown-button');
    const dropdownOptions = document.querySelector('.dropdown-options');
      dropdownButton.addEventListener('click', () => {
      dropdownOptions.style.display = dropdownOptions.style.display === 'none' ? 'block' : 'none';
    });
  </script>
</body>
</html>

Output:

JavaScript Dropdown menu - Interactive program.

Note: Executed on JS Bin

Explanation:

In the above exercise -

First the HTML document creates a dropdown menu with three options: Mathematics, English, and Physics. Here's an explanation of the code:
The <style> section contains CSS styles for the dropdown and its options.
Inside the <body> section, there is a <div> element with the class "dropdown" that acts as a container for the dropdown menu.
Inside the <div>, there is a <button> element with the class "dropdown-button". This button is the visible part of the dropdown menu that users can click to show or hide the options.
Below the button, there is a <ul> element with the id "dropdown-options" and the class "dropdown-options". This is an unordered list of dropdown options.
Inside the <ul>, there are three <li> elements with the class "dropdown-option". These list items represent the available options in the dropdown menu.
In the <script> section, JavaScript code is used to add functionality to the dropdown menu. It selects the dropdown button and dropdown options using document.querySelector() and assigns them to the dropdownButton and dropdownOptions variables.
An event listener is added to the dropdown button using addEventListener(). When the button is clicked, the event listener function is executed.

Flowchart:

Live Demo:

See the Pen javascript-event-handling-exercise-2 by w3resource (@w3resource) on CodePen.

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