test.tsx

interface User {
  id: number;
  name: string;
  address: string;
  wait: boolean;
}

const info = {
  id: "1",
  name: "joe1220",
  address: "joe1220@daum.net",
  wait: false
}

function create_mail(info: User): string {   // what is info's type?
    return `${name}'s id is ${id}. his email address is ${address}.
    The email will be determined based on the wait(${wait}) value. `
};