[TIL] 211123

TypeScript

• ts-node 설치 명령어: npm i -g ts-node
• typescript 모듈 에러
  1. npm i -g typescript
  2. npm link typescript

-기본 타입

// Function
// Optinal parameter
function printUsr(name: string, age?: num) {
  console.log(`Hello ${name} / ${age}`);
}

// Default parameter
function printMsg(msg: string = 'default') {
   console.log(msg);
}

// Rest parameter
function addNums(...nums: number[]): number {
  return nums.reduce((a, b) => a + b);
}


// Array
const sweets1 = string[] = ['cake', 'cookie'];
const sweets2 = Array<string> = ['macaron', 'madeleine'];

// Tuple
let user = [string, number];
user1 = ['coco', 10];


// Alias
type Name = string;
const name: Name = 'coco';
type User = {
  name: string;
  age: number;
};
const user1: User = {
  name: 'coco',
  age: 10
};


// Union - or
type Size = 'small' | 'medium' | 'large';
const size1: Size = 'small';
function selectSize(size: Size) {
  console.log(size);
}


//