How to Install TypeScript and write your first program

TypeScript has become a popular choice for many developers due to its strong typing and excellent tooling support. In this guide, we'll walk you through installing TypeScript and writing your first TypeScript program.

Step 1: Install Node.js and npm

Before installing TypeScript, you need to have Node.js and npm (Node Package Manager) installed. You can download and install them from the official Node.js website.

To check if Node.js and npm are installed, open your terminal and run:

node -v
npm -v

You should see the version numbers for both Node.js and npm.

Step 2: Install TypeScript

Once Node.js and npm are installed, you can install TypeScript globally using npm. Open your terminal and run:

npm install -g typescript

This command installs TypeScript globally on your machine, allowing you to use the tsc command to compile TypeScript files.

To verify the installation, run:

tsc -v

You should see the TypeScript version number.

Step 3: Create Your First TypeScript Program

1. Create a New Directory: Create a new directory for your TypeScript project and navigate into it:

   mkdir my-typescript-project
   cd my-typescript-project

1. Initialize a New Node.js Project: Initialize a new Node.js project to create a package.json file:

   npm init -y

1. Create a TypeScript File: Create a new file named index.ts manually or run this command:

   touch index.ts

1. Write Your First TypeScript Code: Open index.ts in your preferred text editor and add the following code:

   const welcome:string= "Hello World!"

Step 4: Compile TypeScript to JavaScript

To compile your TypeScript code to JavaScript, use the TypeScript compiler (tsc). In your terminal, run:

tsc index.ts

This command generates a index.js file in the same directory.

Step 5: Run the Compiled JavaScript

Now, you can run the compiled JavaScript file using Node.js:

node index.js

You should see the output:

Hello, World!

Follow these steps to set up TypeScript, configure file paths, and write your first TypeScript program.

1. Create a TypeScript Configuration File

   • Create a tsconfig.json file by running:

    tsc --init
   

• This command generates a tsconfig.json file.

1. Configure File Paths

   • Open the tsconfig.json file and set the rootDir and outDir options:

    {
      "compilerOptions": {
        "rootDir": "./module/src",
        "outDir": "./module/dist"
      }
    }
   

2. Create a TypeScript File

   • Create a file named hello.ts inside the module/src directory and add the following code:

    const welcome: string = "Hello World!";
    console.log(welcome);
   

3. Compile TypeScript to JavaScript

   • To convert the TypeScript code to JavaScript, run:

    tsc
   

• This will generate a hello.js file inside the module/dist directory.

1. Run the Compiled JavaScript File

   • Use Node.js to run the compiled JavaScript file:

    node module/dist/hello.js
   

• You should see the output:
  

   Hello, World!
  

By following these steps, you've successfully installed TypeScript, configured file paths, and written and executed your first TypeScript program.