asked on

inheritance and overloading class methods in the subclass

Is it possible to declare a method in a class as overloadable and then overload it in a subclass?
Is there a 'mustoverride' equivalent for 'mustloverload' to force an implementation in a subclass?

example

Public MustInherit Class Beverage2

Public description As String

Overridable Function getDescription() As String
Return description
End Function

End Class

Public Class Pepsi
Inherits Beverage2

Sub New()
description = "pepsi"
End Sub

Public Shadows Function getDescription(v As String) As String
Return description & " "
End Function

End Class

it_saige

Did you mean something like this -

Public MustInherit Class Beverage
	Public MustOverride Property Description() As String

	Public Overridable Shadows Function ToString() As String
		Return Description
	End Function
End Class

Public Class Pepsi : Inherits Beverage
	Private _description As String
	Public Overrides Property Description() As String
		Get
			Return _description
		End Get
		Set(ByVal value As String)
			If Not value.Equals(_description) Then
				_description = value
			End If
		End Set
	End Property

	Public Sub New(ByVal Description As String)
		_description = Description
	End Sub

	Public Overrides Function ToString() As String
		Return MyBase.ToString()
	End Function
End Class

Module Module1
	Sub Main(ByVal args As String())
		Dim drink As Pepsi = New Pepsi("Cool refreshing cola")
		Console.WriteLine(drink.ToString())
		Console.ReadLine()
	End Sub
End Module

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Produces the following output:

-saige-

glenn_r

ASKER

i want to do what you've illustrated but with overloading a method
Is it possible to overload a method of a derived class?

ASKER CERTIFIED SOLUTION

ChloesDad

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glenn_r

ASKER

got it
in all my years doing this i never thought about that one
thanks again
i need to find a pepsi in a vintage glass bottle those are the best!!

it_saige

As ChloesDad stated, there is no way to force overloading of a method. The reason for this is because overloading is optional and overloading a method basically says to the compiler, "I am defining a method that my parent contains. I may choose to use the parent method or just provide a different set of instructions alltogether."

-saige-