Example of Inheritance from Parent Class to a Child Class

[dnixons]

Hi

can anyone give me a code example of how to inherit from a parent class to a child class.

Example:

Parent Class:

CEmployee.vb
Properties: EmpNo, FirstName, LastName, PhoneNo
Methods: Pay, Report


Child Classes:

CPartTimeEmp.vb
CFullTimeEmp.vb


How can i inherit the properties and methods of the parent class (CEmployee) to the child classes (CPartTimeEmp, CFullTimeEmp) how should I start the child classes codes? What will the format be? Any example given will be much appreciated.. Thanks in advance...

[Pirate]

I've customized this little example from one of my lengthy classes when I was training to do this kind of stuff (note : I included some explanation to these classes but you still have to read more about inheritance ) :

'Parent Class
Public Class Price
 
    'Conststans
    Private Const Sandwich_1 As Decimal = 3.0
    Private Const Sandwich_2 As Decimal = 3.5
    Private Const Sandwich_3 As Decimal = 3.95
    Private Const Sandwich_4 As Decimal = 4.5
    Private Price As Decimal
 
 
    'Child Class
    Public Class Sandwiches
        'We start inheritance by using this keyword.
        'It allows us to integrate (use) the Parent'
        'Class variables , properties , methods in 
        'this Child Class . You have also MustInherit
        'directive which forces child to inherits Parent
        'Class ..etc .See list for these keywords and 
        'discription for each one in the Help Files
 
        Inherits Price
        Public Sandwich_ID As Decimal
 
        Public Enum Sandwiches_en
            GLINDA = 1
            THE_Wicked = 2
            Hagatha = 3
            Burt = 4
        End Enum
 
        Public Function SandwichesFunction(ByVal Index As Sandwiches_en) As Decimal
 
            If Index = Sandwiches_en.GLINDA Then
                'See here : We are able to see the Private variables
                'of the Parent Class and we can Get or Set
                'its value , moreover all Methods, Properties
                'of the Parent Class no matter they are 
                'Private of Public , they are still 
                'accessible from anywhere in out Child
                'Class.This applies to the below code also
                Sandwich_ID = MyBase.Sandwich_1
                Return Sandwich_ID
            ElseIf Index = Sandwiches_en.THE_Wicked Then
                Sandwich_ID = MyBase.Sandwich_2
                Return Sandwich_ID
            ElseIf Index = Sandwiches_en.Hagatha Then
                Sandwich_ID = MyBase.Sandwich_3
                Return Sandwich_ID
            ElseIf Index = Sandwiches_en.Burt Then
                Sandwich_ID = MyBase.Sandwich_4
                Return Sandwich_ID
            End If
 
        End Function
 
    End Class
 
 
 
End Class

[sunburnt]

It seems like dnixons example would be better; a full time employee is a subset of an employee; a price is not a subset of a sandwich. In the second case it's more logical to simply have your Sandwich object contain a Price object.

[Pirate]

Originally posted by sunburnt
It seems like dnixons example would be better; a full time employee is a subset of an employee; a price is not a subset of a sandwich. In the second case it's more logical to simply have your Sandwich object contain a Price object.

I know , I said , this is small snap of my very lengthy classes and it's commented out that Price is 'Parent Class' and Sandwiches is 'Child Class' . This is point of this code just to expose the using some inheritance keywords . I think , it should fairly easy to figure out how these methods and properties work together . Keep in mind , one or two or even three examples won't be enough to fully understand Inheritance . He has to read more about it .