🧰 Chapter 2 — Installing Node.js, Deno and TypeScript

Now that you're comfortable using the terminal, it's time to install the tools you'll use to write and run TypeScript code.

In this chapter, you'll learn how to install:

• ✅ Node.js – a JavaScript/TypeScript runtime
• ✅ TypeScript – a language that makes your code safer and easier to read
• ✅ Deno – a modern alternative to Node.js

---

📦 What are these tools?

Tool	Description
Node.js	Runs JavaScript or TypeScript on your machine (outside the browser)
TypeScript	A safer version of JavaScript that helps catch bugs before running your code
Deno	A secure and modern runtime for JavaScript & TypeScript

---

1️⃣ Installing Node.js

To install Node.js correctly and easily, we recommend using a version manager.

A version manager lets you easily switch between different versions of Node.js, which is super useful later when working on multiple projects.

---

🔧 Step-by-step installation using nvm

🟢 Mac / Linux

1. Open your terminal
2. Run this command:

curl -o- https://raw.githubusercontent.com/nvm-sh/nvm/v0.39.7/install.sh | bash

3. Restart your terminal (important!)
4. Then install the latest stable version of Node.js:

nvm install --lts
nvm use --lts

This will install both node and npm automatically.

---

🟦 Windows

Use nvm-windows:

1. Download the .exe from the “Releases” page
2. Install it
3. In a new terminal window:

nvm install lts
nvm use lts

---

🧪 Test your installation

In any terminal:

node -v
npm -v

You should see something like:

v20.12.2
10.7.0

If yes — you’re good to go 🎉

---

🔄 How to update Node.js later

Just run:

nvm install --lts
nvm use --lts

You can even switch between versions:

nvm list
nvm use 18

---

2️⃣ Installing TypeScript

You can install TypeScript globally using npm (which came with Node.js):

npm install -g typescript

This gives you the tsc (TypeScript Compiler) command.

🧪 Test your installation

tsc -v

You should see something like:

Version 5.4.5

---

🔄 How to update TypeScript

To always have the latest version:

npm install -g typescript

You can check it worked by running:

tsc -v

If you want a specific version, use:

npm install -g typescript@5.3.3

---

3️⃣ Installing Deno

Deno is a newer, secure runtime made by the original creator of Node.js. It runs TypeScript natively (no compiler setup needed).

🔧 Install it

On Mac/Linux:

curl -fsSL https://deno.land/install.sh | sh

On Windows (PowerShell):

iwr https://deno.land/install.ps1 -useb | iex

You may need to restart your terminal after install.

🧪 Test your installation

deno --version

You should see:

deno 1.43.1
typescript 5.x.x
v8 12.x.x

---

🔄 How to update Deno

Deno has a built-in upgrade command:

deno upgrade

That's it — it will fetch and install the latest version automatically.

You can re-run deno --version to confirm the update.

---

✅ Recap

Here are the commands you now have:

Command	Purpose
node	Run JavaScript or .js files
npm	Install libraries and tools
tsc	Compile TypeScript to JavaScript
deno run	Run TypeScript files directly

---

🧠 Tip: Why both Node and Deno?

Most projects today use Node.js — it’s the industry standard. But Deno is growing fast and is used heavily in Socle Commun. Learning both gives you more flexibility and confidence.

---

▶️ What’s next?

Let’s use all this and actually write and run your first TypeScript file — the fun part!

👉 Go to Chapter 3: Writing and Running TypeScript