JavaScript - Form & Document Events

Overview

Estimated time: 15–20 minutes

Form and document events let you respond to user input, validation, and document state changes.

Learning Objectives

• Handle form submission, input, and change events.
• Respond to document loading and visibility events.

Prerequisites

• JavaScript - Mouse & Keyboard Events

Form Events

form.addEventListener('submit', function(event) {
  event.preventDefault();
  // Validate and process form
});
input.addEventListener('input', function(event) {
  // Live update
});

Document Events

document.addEventListener('DOMContentLoaded', function() {
  // DOM is ready
});
document.addEventListener('visibilitychange', function() {
  // Tab visibility changed
});

Common Pitfalls

• Forgetting to prevent default form submission can cause page reloads.

Summary

Form and document events are essential for modern, interactive web applications.