TypeScript

TypeScript - JavaScript with Type Checking

TypeScript is JavaScript with added syntax for types.

TypeScript is a syntactic superset of JavaScript which adds static typing.

This basically means that TypeScript adds syntax on top of JavaScript, allowing developers to add types.

TypeScript being a "Syntactic Superset" means that it shares the same base syntax as JavaScript, but adds something to it.

Benefits

• Static typing
• Code completion
• Refactoring
• Shorthand notations

Drawbacks

• Compilation
• Discipline in coding

TypeScript Compiler

TypeScript is transpiled into JavaScript using a compiler.

TypeScript being converted into JavaScript means it runs anywhere that JavaScript runs!

TypeScript - Medium to large projects JavaScript - Simple projects

Setting up development environment

Installing the Compiler

TypeScript has an official compiler which can be installed through npm.

npm install -g typescript

We can check typescript version by using this command.

tsc -v

Hello World! Example

Suppose if you want to compile ts file,

Eg: index.ts

Then use do like this,

tsc index.ts

This will generate a new index.js file.

Configuring the TypeScript compiler

By default the TypeScript compiler will print a help message when run in an empty project.

The compiler can be configured using a tsconfig.json file.

You can have TypeScript create tsconfig.json with the recommended settings with:

tsc --init

Remember the modifications you have to do in tsconfig.json for that just open that config file once.

Feom now onwards use tsc to complie the program because we did required changes in config file.

Built-in Types

JavaScript

• number
• string
• boolean
• null
• undefined
• object

TypeScript

• any
• unknown
• never
• enum
• tuple

To compile

tsc

To execute

node dist/index.js