Lecture 7: Introduction to JavaScript – The Basics

Welcome back, coding enthusiasts! 🎉 Ready to take your front-end development skills to the next level? In this lecture, we’ll be diving into JavaScript, the programming language that makes web pages interactive and dynamic!

What is JavaScript?

JavaScript is a programming language that allows you to add interactive elements to your websites. Whether it’s changing the content on the page without refreshing, responding to user clicks, or even validating forms before submission, JavaScript makes it all happen!

Why Learn JavaScript?

JavaScript is essential for modern web development. It allows you to manipulate HTML and CSS dynamically, giving you the ability to create highly interactive websites. Without JavaScript, your websites would be static and unable to respond to user interactions in real-time.

It’s also the foundation of many powerful web technologies, including popular frameworks like React, Angular, and Vue.js, which makes JavaScript a must-learn language for anyone serious about web development.

Setting Up Your First JavaScript Code

Before we dive into writing JavaScript, let's set up the basics. JavaScript can be added to an HTML document in two ways:

• Inline: By adding JavaScript code directly inside HTML tags.
• External: By linking to an external JavaScript file (.js).

Here's how to add JavaScript inline inside your HTML document:

This example creates a button that shows a pop-up alert when clicked. The onclick attribute calls a JavaScript function to display the message.

JavaScript Syntax

Now that we’ve seen how to add JavaScript to an HTML page, let’s take a quick look at the basic syntax you’ll be using:

• Variables: Variables store data values, which can be numbers, text, or even complex objects.

let name = 'John Doe';

• Functions: Functions are blocks of code that perform a specific task when called.

  function greet() {
    alert('Hello, World!');
  }
  

• Events: JavaScript allows you to respond to user actions like clicks, key presses, or form submissions.

  document.getElementById('myButton').addEventListener('click', function() {
    alert('Button clicked!');
  });
  

Next Steps:

Now that you have a basic understanding of JavaScript, it’s time to practice! Here are a few exercises to help you get started:

• Write a function that shows an alert with your name when the user clicks a button.
• Try creating a small interactive form that validates user input (like checking if the user entered their name).

In our next lecture, we’ll dive deeper into JavaScript’s control flow, including if statements and loops. But for now, keep experimenting with the code you’ve learned and start building simple interactive elements on your web pages!

Until next time, happy coding! 🌐💻