JavaScript Introduction

Overview

• Starting a new series on JavaScript from beginner to advanced level.
• Focus of this video: Introduction to JavaScript and writing a simple "Hello World" program.

What is JavaScript?

• JavaScript is a programming language, similar to Java, C, C++, etc.
• Primarily made for web applications to add functionality.
• Common misconception: JavaScript is related to Java; this is false.
  • Example: The word "car" in "carpet" has no relation; similarly, Java and JavaScript are unrelated.
  • JavaScript is a standalone language.

How to Use JavaScript

• Two methods to include JavaScript in web applications:
  1. Internal Linking: Write JavaScript code directly inside the HTML file.
  2. External Linking: Create a separate .js file and link it to the HTML.

Internal Linking Example

• Create an index.html file with basic HTML structure:
  • Use the <script> tag for JavaScript code.
  • Example of printing to the console:

    console.log("Hello World");
    

  • Access output via browser's console (Inspect element > Console).

External Linking Example

• Create a script.js file to hold the JavaScript code.
• Link it in the HTML:

  <script src="script.js"></script>
  

• Code example in script.js:

  console.log("This is a hello from external.js file");
  

Combining Internal and External Scripts

• You can mix internal and external scripts in the same HTML document:
  • Order of scripts matters (runs top to bottom).
• Example of including multiple scripts:

  <script src="script.js"></script>
  <script>console.log("Hey again from internal script");</script>
  

Key Takeaways

• JavaScript can be linked internally or externally; external linking is preferred for larger projects.
• Use of <script> tag for both internal and external links.
• Multiple JavaScript files can be linked and executed in a sequence.

Conclusion

• This video covered the basics of JavaScript, including how to write a "Hello World" program and the best practices for linking JavaScript in HTML.
• Upcoming videos will delve deeper into JavaScript concepts.