JavaScript Introduction

What is JavaScript and why learn it?

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JavaScript is the world's most popular programming language. JavaScript is the programming language of the Web. JavaScript is easy to learn.

What JavaScript Can Do

1JavaScript can change HTML content (document.getElementById("demo").innerHTML = "Hello JS").

2JavaScript can change HTML attribute values (element.src = "new.png").

3JavaScript can change HTML styles (CSS) (element.style.color = "red").

4JavaScript can hide or show HTML elements.

5JavaScript handles network requests (API calls) seamlessly in the background.

Interactive DOM Modification

Try It Yourself »

<div>
  <h2 id="heading">Hello World!</h2>
  <button onclick="changeText()" style="padding: 8px 16px; background: #04AA6D; color: white; border: none; border-radius: 4px; cursor: pointer;">
    Click to Change Text
  </button>
  
  <script>
    function changeText() {
      const el = document.getElementById("heading");
      el.innerText = "JavaScript changed me dynamically! ✨";
      el.style.color = "#04AA6D";
    }
  </script>
</div>

Google AdSense Slot (inContentBanner)

Set your Publisher ID in src/config/ads.ts to display live ads.

Test Yourself With Exercise

+15 XP

Which method is used to select an HTML element by its ID attribute in JavaScript?

Next: JavaScript Variables & Data Types »