Summary - TypeScript basics

Write your first TypeScript program by combining setup, tsc, and tsconfig.

Summary - TypeScript basics

TypeScript is a typed superset of JavaScript. The tsc compiler turns .ts files into .js while checking types. With tsconfig.json you set the compile options and the target JS version.

// app.ts
let mesaj: string = "Merhaba TypeScript";
console.log(mesaj);
// Compile: tsc app.ts
// Run: node app.js

This way you write a safe program that catches errors early.

Exercise Your first TypeScript program

Declare a variable ad with type string and value "TS". Declare a variable selam with type string and value "Öğreniyorum ". Then print the concatenation selam + ad with console.log.

Show example solution

let ad: string = "TS";
let selam: string = "Öğreniyorum ";
console.log(selam + ad);

Test yourself

Which file specifies the compiler options in a TypeScript project?
- package.json
- README.md
- tsconfig.json
- .gitignore
Show answer

tsconfig.json — tsconfig.json tells tsc the target JS version, the output folder, and which files to compile. package.json lists package dependencies.

Type annotation

let mesaj: ____ = "Merhaba TypeScript";

Show answer

let mesaj: string = "Merhaba TypeScript";

TypeScript core parts

tsc

Compiler
tsconfig.json

Configuration
.ts

Source extension
target

JS version

Next lesson: string type

We Are Enhancing Your Experience

Cookie Preferences

Strictly Necessary Cookies

Analytical Cookies