/YinHk-typescript

TypeScript cheatsheet and notes

YinHk-TypeScript

TypeScript cheatsheet and notes

What is TypeScript?

  • TypeScript is JavaScript with syntax for types, and some additional features like generics, interface etc.
  • TypeScript is a typed superset of JavaScript that compiles to plain JavaScript.
  • TypeScript is a Object-Oriented programming.
  • TypeScript Code is converted into Plain JavaScript Code:  TypeScript code can’t be natively interpreted by browsers. So if the code was written in TypeScript, it gets compiled and converted into JavaScript before execution.

use typescript

via npm

npm install -g typescript

npm install typescript --save-dev

npx tsc --init        # generate tsconfig.json

Compile and Execute a TypeScript Program

npx tsc index.ts

After compiled, it will change to js file, then execute the js file by nodejs

$ node index.js

Note − Multiple files can be compiled at once:

npx tsc file1.ts, file2.ts, file3.ts

ts-node ts-node is a TypeScript execution engine and REPL for Node.js.

# Execute a script as `node` + `tsc`.
ts-node script.ts