Summary  
This chapter shows how to install and configure the TypeScript compiler, create typed .ts files that enable printing, and transpile them into JavaScript using tsc and a tsconfig.json.

General domain of usage  
Server-side JavaScript development with Node.js


To work with TypeScript, you need to install it and configure your project.

TypeScript does not run directly in Node.js. Instead, it compiles into regular JavaScript, which can then be executed.

### Installing TypeScript

You can install TypeScript globally using npm:

```bash
npm install -g typescript
```

After installation, you can check the version:

```bash
tsc -v
```





### Creating a TypeScript File

Create a new file with the `.ts` extension:




const message: string = "Hello, TypeScript";
console.log(message);



### Compiling TypeScript to JavaScript

To convert a TypeScript file into JavaScript, use the TypeScript compiler:

```bash
tsc index.ts
```

This will generate a new file:

```bash
index.js
```

You can then run it with Node.js:

```bash
node index.js
```





### Using a tsconfig File

In real projects, TypeScript is configured using a `tsconfig.json` file.

You can generate it with:

```bash
tsc --init
```

This file defines how TypeScript compiles your code.

For now, you don't need to change much inside it. The default configuration is enough to get started.


Learn the fundamentals of TypeScript and apply them to backend development. Define types, structure data, and organize code using functions and classes to prepare for building applications with Nest.js.

Setting Up TypeScript

Installing TypeScript

Creating a TypeScript File

Compiling TypeScript to JavaScript

Using a tsconfig File