Typescript wild tuto

type User = {
    name: string;
    age: number;
    birthday?: string|Date;
    };
const prettyPrintWilder = (users: User[]) => {
    console.log("########################");
    users.map((el) => {
        console.log(`${el.name} is ${el.age} years old`);
    });
    console.log("########################");
    };
    const wilders: User[] = [];
    const user1 = { name: "Pierre", age: 23 };
    const user2 = { name: "Paul", age: calculateAge("10/02/1990") };
    const user3 = { name: "Jacques", age: 25 };
    wilders.push(user1);
    wilders.push(user2);
    wilders.push(user3);
    prettyPrintWilder(wilders);

  function calculateAge(birthday:string){
    let birth = new Date(birthday)
    let yearBirth = birth.getFullYear();
    let today = 2020;
    return today - yearBirth;
  }