1.タイプ別

1) string, number, boolean

const name: string = "sj"
const age: number = 26
const hasGirlFriend: boolean = false

2) array

①資料の種類が同じ場合

const nickname: string[] = ["a","b","c","d"]
const age: number[] = [1,2,3,4]

②資料型が多い場合

const nickname: (string|number)[] = ["a",1,"b",2]
const age: (number|boolean)[] = [1,true,2,false]

3) object

const myInfo: {
 name: string
 age: number
 hasGirlFriend: boolean
}= {
	name: "sj",
  	age: 26,
  	hasGirlFriend: false
}

4) function

function getMyNickname(name: string):string{
  	const nickname = `cool ${name}`
 	return nickname 
}

const getMyNickname = (name?: string):string => {
  	const nickname = `cool ${name}`
 	return nickname 
}

5) Union

const age: string|number = 26 // or "26"

6）小整理

2.タイプ変数(type alias)

type AgeType = string | number
const age: AgeType = 26 // or "26"

1)宣言関数はタイプ変数を許可しない

type GetMyNickNameType = (name:string|number) => string;

function getMyNickname(name){
  	const nickname = `cool ${name}`
 	return nickname 
}
// 선언 함수에서는 타입변수 사용불가하더라

const getMyNickname:GetMyNickNameType = function(name){
  	const nickname = `cool ${name}`
 	return nickname 
}
const getMyNickname:GetMyNickNameType = (name) => {
  	const nickname = `cool ${name}`
 	return nickname 
}

2）対象

① [key: string]

type MemberType = {
	[key: string]: string
}

const member :MemberType = {
	lastName: "choi",
  	FirstName: "sj",
  	hobby: "walk",
  	job: "student"
  	~~~ // value가 string이기만 하면 된다.
}

②オブジェクトはタイプではなくインタフェースが好き

interface IStudent{
  	name: string
}
interface ITeacher extends IStudent{
 	subject: string 
}

const student: IStudent = {name: "choi"}
const teacher: ITeacher = {name: "park", subject: "korean"}

interface IStudent{
  	name: string
}
interface IStudent{
 	age: number 
}

IStudent // === {name:string, age:number} 

③readonly（推奨文字）

type FriendsName = {
	readonly name: string
}
const friends :FriendsName = {
	name: "park"
}