Which class design is better?

Which class design is better and why?

public class User
{
    public String UserName;
    public String Password;
    public String FirstName;
    public String LastName;
}

public class Employee : User
{
    public String EmployeeId;
    public String EmployeeCode;
    public String DepartmentId;
}

public class Member : User
{
    public String MemberId;
    public String JoinDate;
    public String ExpiryDate;
}

OR

public class User
{
    public String UserId;
    public String UserName;
    public String Password;
    public String FirstName;
    public String LastName;
}

public class Employee
{
    public User UserInfo;
    public String EmployeeId;
    public String EmployeeCode;
    public String DepartmentId;
}

public class Member
{
    public User UserInfo;
    public String MemberId;
    public String JoinDate;
    public String ExpiryDate;
}

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The question is simply answered by recognising that inheritance models an "IS-A" relationship, while membership models a "HAS-A" relationship.

An employee IS A user

An employee HAS A userinfo

Which one is correct? This is your answer.

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I don't like either one. What happens when someone is both a member and an employee?

---

Ask yourself the following:

Do you want to model an Employee IS a User? If so, chose inheritance.

Do you want to model an Employee HAS a User information? If so, use composition.

Are virtual functions involved between the User (info) and the Employee? If so, use inheritance.

Can an Employee have multiple instances of User (info)? If so, use composition.

Does it make sense to assign an Employee object to a User (info) object? If so, use inheritance.

In general, strive to model the reality your program simulates, under the constraints of code complexity and required efficiency.

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