タイプ別名

interfaceに似ています.別名として、自分で作成するタイプを指定します.
⭐ primitive

type MyStringType = string;

const str = 'world';
let myStr : MyStringType = 'hello';
myStr = str;

呑呑呑ユニオンタイプ(AでもBでも可)

let person:string |number = 0;
person = 'Mark';

type StringOrNumber = string|number;
let another: StringOrNumber = 0;
another = 'Anna';

⭐ Typle

let people: [string,number] = ['Mark',35];
type PersonTuple = [string,number];
let other: PersonTuple = ['Anna', 25];

⭐ Function

type EatType = (food:string) => void;