TypeScript Hello World Program – Code Sample

This article represents code samples on writing Hello World program with TypeScript. Please feel free to comment/suggest if I missed to mention one or more important points. Also, sorry for the typos.

• Setting up Typescript Development environment
• TypeScript Hello World Program

Setting up Typescript Development environment

Use the instructions on following page to setup the TypeScript development environment. Docker – How to setup Typescript Development Environment

TypeScript Hello World Program

interface Person {
    firstname: string;
    lastname: string;
}

function hello(person: Person) {
    return "Hello, " + person.firstname + " " + person.lastname;
}

var calvin = {firstname: "Calvin", lastname: "Hobbes"};
var chris = {firstname: "Chris", lastname: ""};

console.log(hello(calvin));
console.log(hello(chris));

Name the above program as “hello.ts”. Compile it using the command, “tsc hello.ts”. It would create the file “hello.js”. Execute the “hello.js” using node runtime using following command:

node hello.js

It would print following:

Hello, Calvin Hobbes
Hello, Chris