Lesson 2: The Built-in Types - Intro to TypeScript

The Built-in Types Meet the three types you'll use most: string, number, boolean.

1const coder: string = "Ada";

2const age: number = 10;

3const likesPizza: boolean = true;

4console.log(`${coder} is ${age} and likes pizza: ${likesPizza}`);

Terminal

$ npx tsc main.ts

$ node main.js

Ada is 10 and likes pizza: true

Every line, explained

const coder: string = "Ada";: string is the type for text. The built-in type names are all lowercase: string, number, boolean.
const age: number = 10;: number covers every kind of number: whole numbers and decimals alike. (Some languages split these in two; TypeScript keeps it simple.)
const likesPizza: boolean = true;: boolean allows exactly two values: true or false.
console.log(`${coder} is ${age} and likes pizza: ${likesPizza}`);: console.log(...) works exactly as it does in JavaScript; TypeScript IS JavaScript underneath, so everything from Intro to JavaScript still applies. Template literals with ${...} work in TypeScript too.