타입스크립트에서 자바스크립트 코드에 타입을 정의하는 방법은 : 를 사용한다.
let str: string = 'hello';
let num: number = 2;
let isTrue: boolean = true;
let arrnum: number[] = [1,2,3];
let arrstr : string[] = ['hi', 'hello'];
let arrnum: Array<number> = [1,2,3];
let tuple:[string, number] = ['hi', 3];
tuple[1].('!'); // Error, 'number' does not have 'concat'
tuple[5] = 'hello'; // Error, Property '5' does not exist on type '[string, number]'.
enum Desserts { Cake, Macaron, Cookies }
let dessert: Desserts = Desserts.Cake;
enum Desserts {Cake, Macaron, Cookies}
let dessert:Desserts = Desserts[0];
enum Desserts {Cake = 3, Macaron, Cookies}
let dessert:Desserts = Desserts[3]; //Cake
let unuseful: void = undefined;
function notuse(): void {
console.log('sth');
}
function neverEnd(): never {
while (true) {
}
}