4. Node.js REPL – The Interactive JavaScript Playground

REPL is one of the most powerful features of Node.js for beginners and developers. It allows you to run JavaScript code instantly without creating a file.

REPL stands for Read – Evaluate – Print – Loop.

1. What is REPL?

REPL is an interactive shell where you can write JavaScript code and get output immediately.

• Testing code
• Debugging
• Learning JavaScript
• Quick calculations

2. How to Start REPL

Type:

node

You will see:

>

3. Simple Examples

Math

10 + 20

Output:

30

Variables

let name = "Node.js"
name

Output:

Node.js

4. Multi-line Code

function add(a, b) {
  return a + b;
}

add(5, 5);

5. Special Commands

• .help
• .clear
• .save file.js
• .load file.js
• .exit

6. Previous Output

5 + 5
_

REPL is great for testing, but real apps should use files.

Conclusion

Now you can test JavaScript instantly using Node.js REPL.

Your journey is getting interactive ⚡🚀