0

I'm having a problem that I cant figure out, I'm trying to code a payroll system with vb.net 2013, I must use a console application.

I'm using classes to calculate the salary depending on the amount of weeks that the employee's worked, but the problem is that I cannot inherit from my parent class, I keep on getting this error and i don't know how to fix it.

Error 2 Class 'Employee_Payment_System.Employee' has no accessible 'Sub New' and cannot be inherited.

Whenever i try to add a 'sub new' I get this

Error 3 'Public Sub New()' has multiple definitions with identical signatures.

Here is my code so far

Public Class Employee #Region "Private Declarations" Private EMP_FullName As String Private EMP_LastName As String Private EMP_Salary As Double Private EMP_Number As Integer Private EMP_Address As String #End Region 'The values are obtained from the public properties coded below Private Sub New() EMP_FullName = "" EMP_LastName = "" EMP_Salary = 0.0 EMP_Address = "" End Sub Private Sub New(ByVal FullName As String, ByVal LastName As String, ByVal Address As String, ByVal Salary As Double, ByVal Number As Integer) EMP_FullName = FullName EMP_LastName = LastName EMP_Address = Address EMP_Number = Number EMP_Salary = Salary End Sub ' the properties gets their values from the console Public Property FullName() As String Get Return EMP_FullName End Get Set(value As String) EMP_FullName = value End Set End Property Public Property LastName() As String Get Return EMP_LastName End Get Set(value As String) EMP_LastName = value End Set End Property Public Property Address() As String Get Return EMP_Address End Get Set(value As String) EMP_Address = value End Set End Property Public Property Salary() As Double Get Return EMP_Salary End Get Set(value As Double) EMP_Salary = value End Set End Property Public Property Number() As Integer Get Return EMP_Number End Get Set(value As Integer) EMP_Number = value End Set End Property Public Overridable Function Payment() As Double Return EMP_Salary End Function End Class Public Class WeeklySalary : Inherits Employee 'The main problem "Error 2 Class 'Employee_Payment_System.Employee' has no accessible 'Sub New' and cannot be inherited." generates here Sub New()' I get my second error "Error 3 'Public Sub New()' has multiple definitions with identical signatures. " here End Sub Private NumberOfWeeks As Integer Private Sub New() 'The second Error is related to this sub NumberOfWeeks = 0 End Sub Public Sub New() NumberOfWeeks = Number End Sub Public Property Number_Of_Weeks() As Integer 'This is the number of weeks worked Get Return NumberOfWeeks End Get Set(value As Integer) NumberOfWeeks = value End Set End Property Public Overrides Function Payment() As Double Return NumberOfWeeks * Salary 'Calculates Weekly salary here End Function End Class

I still have to code one more Class for monthly payments, and I still need to code the module for the console interface but I need my classes to work before I can start the module (For testing purposes).

Improve this question
1
  • 2
    So what don't you understand about the errors you're getting? Why make New private? Commented Nov 3, 2015 at 8:34

3 Answers 3

Reset to default
1

Okay I have managed to fix it, I have changed my private constructors to public and it worked thank you

Improve this answer
Sign up to request clarification or add additional context in comments.

Comments

0

As jonrsharpe says: Why are you making your constructors (Sub New) private? When adding a Public Sub New without parameters it clashes with Private Sub New(). You cannot have to methods with the same name and foot print. But what are you trying to achieve by inheriting from Employee? If you are trying to do some EmployeeWorkRecord class it should probably aggregate Employee and work records and not inherit from it.

Improve this answer

1 Comment

"Protected" would work, though. But yeah, don't really see the use.
0

I'm not writing this as a criticism, just as a general pointer about inheritance.

The idea of inheritance is that child classes are the same kind of object as the parent class, but with extra functionality.

To have a real world comparison, Somebody's wages aren't the same as the somebody.

However you could have for example a class Human. A child class of that could be an employee while another child class could be a customer. Each with their own properties.

An employee could have a StartOfEmployment property while a customer could have for example a LoyaltyCardPoints property, and they could both have ContactAddress and Gender.

Anyway. To the answer - or one possible one at any rate

I suspect that you're looking at inheritance the wrong way round. The employee could possibly inherit the WeeklySalary class, while a class of Manager could possibly inherit from a MonthlySalary Class. But you'd probably be better setting up some sort of datatable using employee numbers as a key. if you do it the way youre doing at the moment, you'd have a lot of either duplicated or unused data in your program.

The naming of parent and child classes sometimes is counter intuitive as we often think as children as being smaller than the parents, but in programming, the child is the same as the parent but with extra funtionality.

Improve this answer

1 Comment

In a nutshell: Inheritance = "X is a Y" Composition = "X has a Y" - also, the old adage "Favour composition over inheritance"

Start asking to get answers

Find the answer to your question by asking.

Ask question

Explore related questions

See similar questions with these tags.