❌

interface User {
  name: string;
  age: number;
  gender?: string;
  readonly birthYear: number;
}

let user2:User = {
  name: 'aaa',
  age: 30,
  birthYear: 1990,
}

<u>user2.birthYear = 2000</u>

Cannot assign to  birthYear  because it is a read-only property.

read-only property는 수정이 불가하다.

초기값을 활용하는 것만 가능!

⭕️

interface User {
  name: string;
  age: number;
  gender?: string;
  readonly birthYear: number;
}

let user2:User = {
  name: 'aaa',
  age: 30,
  birthYear: 1990,
}

console.log(user2.birthYear); //1990