The Code

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Public Class Form83
    

        '## Example 20.2 : Shopping Cart ##
        '## In this example, we add a few Labels, two Buttons, ## 
        '## and six Check Boxes. We declare the price of each item using the Const                          Keyword. ##

        '## If a Checkbox is being ticked, its state is True else its state is False. ##
        '## To calculate the total amount of purchase, ##
        '## we use the mathematical operator +=. For example, sum+=BN is actually                      sum=sum+BN. ##

        '## Finally, we use the ToString method to display the amount in currency. ##

 

        '## Dimension Variables using (Const) Declaration ##

        '## Indicate Value is a Constant & Cannot be Changed ##

 

   Private Sub Button1_Click(sender As Object, e As EventArgs) Handles Button1.Click

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        Const large As Integer = 10.0
        Const medium As Integer = 8
        Const small As Integer = 5

        Dim sum As Integer

        Dim c As String = "n2"

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        If CheckBox1.Checked = True Then
            sum += large
        End If

        If CheckBox2.Checked = True Then
            sum += medium
        End If

        If CheckBox3.Checked = True Then
            sum += small
        End If

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        Label1.Text = sum.ToString("c")

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    End Sub

    
   

  
    Private Sub Button2_Click(sender As Object, e As EventArgs) Handles Button2.Click

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        CheckBox1.Checked = False
        CheckBox2.Checked = False
        CheckBox3.Checked = False
        Label1.Text = ""

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    End Sub

End Class