Polymorphism

Public Class CMultiple
    Inherits CQuestion
    Private m1 As String
    Private m2 As String
    Private m3 As String
    Private m4 As String
 
 
 
    Public Sub New(ByVal qnum As Int16, ByVal question As String, ByVal a1 As String, ByVal a2 As String, ByVal a3 As String, ByVal a4 As String)
        MyBase.mQuestionNumber = qnum
        MyBase.mquestion = question
        m1 = a1
        m2 = a2
        m3 = a3
        m4 = a4
    End Sub
    Public Overrides Sub PrintQuestion(ByRef test As String)
 
    End Sub
End Class
 
---------------------------------
 
Public Class CTrueFalse
    Inherits CQuestion
    Public Sub New(ByVal qnum As Int16, ByVal question As String)
        MyBase.mQuestionNumber = qnum
        MyBase.mquestion = question
    End Sub
    Public Overrides Sub PrintQuestion(ByRef test As String)
 
    End Sub
End Class
 
---------------------------------------------------
 
Public MustInherit Class CQuestion
    Protected mQuestionNumber As Int16
    Protected mquestion As String
    Public MustOverride Sub PrintQuestion(ByRef test As String)
 
End Class
------------------------------------------------
 
Public Class frmMain
    Private arQ(4) As CQuestion
    Private test As String
    Private Sub frMain_Load(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MyBase.Load
        test = "test"
        test &= vbNewLine & vbNewLine
    End Sub
 
    Private Sub BtnAdd_Click(ByVal sender As Object, ByVal e As System.EventArgs) Handles BtnAdd.Click
        Dim qnum As Int16
        If qnum < 5 Then
 
 
 
            arQ(qnum) = New CTrueFalse(qnum + 1, TxtQuestion.Text)
 
            qnum += 1
 
        End If
 
 
 
    End Sub
 
    Private Sub BtnMultiple_Click(ByVal sender As Object, ByVal e As System.EventArgs) Handles BtnMultiple.Click
        Dim qnum As Int16
 
        arQ(qnum) = New CMultiple(qnum + 1, TxtQuestion.Text, TxtA.Text, TxtB.Text, TxtC.Text, TxtD.Text)
 
 
    End Sub
 
    Private Sub BtnPrint_Click(ByVal sender As Object, ByVal e As System.EventArgs) Handles BtnPrint.Click
        
 
 
 
 
        Dim intX, intY As Integer
 
        intY = arQ.Length
 
        For intX = 0 To (intY - 1)
 
            If arQ(intX) IsNot Nothing Then
 
                arQ(intX).PrintQuestion(test)
 
            End If
 
        Next
        MsgBox(test)
    End Sub
End Class

                                  

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