[TS] 타입선언

• props에서 타입선언

const sum = (a: number, b: number) => {
	return a + b;
}

• 대표적 기능 : Interface, Generic, Decorators

interface User {
  id: number;
  name: string;
}

function greetingUser(user: User) {
	 console.log(`Hello, ${user.name}!`)
}

const parkUser = {
	id: 1,
  name: "박해커"
};

greetingUser(parkUser);

• 타입 종류

//Boolean
let isShow: boolean = true;
let isDone: boolean = false;

//Number
let number1: number = 5;
let number2: number = 0.7;

//String
let firstName: string = "coding";
let lastName: string = 'kim';
let longString: string = `hi`;

//Array 타입선언(방법두가지)
let items: string[] = ["apple", "banana", "grape"];
let numberList : Array<number> = [4, 7, 100];

//Tuple
let user: [string, number, boolean] = ["hojun", 20, true];

//Object 
let user: {name: string, age: number} = { 
	name: "kimcoding",
    age: 20
}

//Any (엄격한 타입검사를 안함)
let maybe: any = 4;