Understanding Typescript

This is a basic project to study typescript.

Starting project

To start the playground project please run below command.

1. Install project requirements.

npm install

2. Start project on localhost:3000

npm start

Installing typescript to your local

To install the typescript please run below command. It will install typescript globally to your machine.

npm install -g typescript

If you don't have node js on your local machine first install node js from below link.

https://nodejs.org/de/download/

Compiling Typescript

To compile your typescript files please run with below command.

tsc filename.js

Output of the typescript

As you can see we have 2 folders in the project which are src and dist.

src folder contains our ts file and dist folder contains our output js files.

Core datatypes

Union type, Literal type and Aliases

See examples in the union-alias-literal.ts

Functions

See examples in the functions.ts

Unknown type and never type

See examples in the unknown-never.ts

Typescript Compile

Recompile automatically with watch command

Run your typescript command with --watch or -w keyword to compile every changes in your ts file.

Instead of

tsc app.ts

run

tsc app.ts -w

Recompile automatically whole project

Create tsconfig.json file with below command.

tsc --init

After creation of tsconfig file you can run below command to compile all ts files in your project even with watch feature.

tsc -w