Node.js NPM

Node.js NPM (Node Package Manager)

NPM stands for Node Package Manager.
It is the world’s largest software registry, used to install, manage, and share JavaScript packages.

Whenever you install Node.js → NPM is automatically installed.

⭐ What Is NPM Used For?

✔ Installing packages (libraries, frameworks)
✔ Managing project dependencies
✔ Running scripts
✔ Sharing your own packages
✔ Creating and managing Node.js projects

1️⃣ Check NPM Version

Check Node.js version:

2️⃣ Initialize a New Node.js Project

Creates package.json:

For quick setup (no questions):

3️⃣ Installing Packages

There are three types of installs:

📌 A. Local Installation (most common)

or shorthand:

Creates:

• node_modules/

• Adds entry in package-lock.json

But NOT added to package.json unless you add --save (older versions) or use the next method.

📌 B. Save to dependencies (for production use)

OR in modern npm:

Automatically goes to:

📌 C. Save to devDependencies (development only)

Example: nodemon, typescript

Gets added to:

4️⃣ Install Packages Globally

Global packages are installed system-wide.

Example: nodemon CLI tool

Check global packages:

5️⃣ Uninstall Packages

Local uninstall:

Global uninstall:

6️⃣ Updating Packages

Update a package:

Update all:

7️⃣ Installing Specific Versions

8️⃣ NPM Scripts

You can run custom scripts defined in package.json:

package.json

Run:

OR

9️⃣ Understanding package.json

package.json stores project configuration:

🔟 package-lock.json

Auto-generated file.
It stores the exact versions installed.

✔ Ensures consistent installation
✔ Used during deployments

1️⃣1️⃣ node_modules Folder

Stores all installed dependencies.

⚠ Never upload this folder to GitHub
Use .gitignore

To rebuild dependencies:

⭐ BONUS: Useful NPM Commands

NPM vs NPX

Example: