[Typescript] Access modifiers

foo.ts

// make sure access modifier are stated (e.g public , private)
// adding readonly for not needed to be modified

export class User {
    public readonly id: number;
    public firstName: string;
    public lastName: string;
    public email: string;
    protected dob: Date;

    public get fullName(): string {
        return `${this.firstName} ${this.lastName}`;
    }

    public doesEmailMatch(email: string): boolean {
        return this.email === email;
    }
}

// creating private method accesible in the class

export class Admin extends User {
    public readonly yearBorn: number;

    constructor(firstName: string, lastName: string, email: string) {
        super();
        this.firstName = firstName;
        this.lastName = lastName;
        this.email = email;
        this.yearBorn = this.getYear();
    }

    private getYear(): number {
        return this.dob.getFullYear();
    }
}