INTRODUCTION TO USING DO LOOPS

FROM LESSON 4: LOOP TEST




   Private Sub btnDoWhile_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles btnDoWhile.Click

        '---this is a pre-test loop

        lbAnswer.Items.Clear()
        Dim strPIN As String

        'test to see if PIN=Ron at first

        Do While strPIN <> "Ron"
            strPIN = InputBox("Enter your PIN:", "LogIN")
        Loop
        lbAnswer.Items.Add(strPIN)

    End Sub

    Private Sub btnDoWhile2_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles btnDoWhile2.Click

        '----this is a post-test


        lbAnswer.Items.Clear()
        Dim strPIN As String

        'make them enter a PIN at least once
        Do
            strPIN = InputBox("Enter your PIN:", "LogIN")
        Loop While strPIN <> "Ron"
        lbAnswer.Items.Add(strPIN)

    End Sub

    Private Sub btnDoUntil_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles btnDoUntil.Click
        '---this is a pre-test loop

        lbAnswer.Items.Clear()
        Dim strPIN As String

        'test to see if PIN=Ron at first

        Do Until strPIN = "Ron"
            strPIN = InputBox("Enter your PIN:", "LogIN")
        Loop
        lbAnswer.Items.Add(strPIN)

        '========================================
        '---this is a post-test loop

        'Do
        '    strPIN = InputBox("Enter your PIN:", "LogIN")
        'Loop Until strPIN = "Ron"

        'lbAnswer.Items.Add(strPIN)

        '========================================



    End Sub
    End Sub