BasicFunctionProc.vb

Public Class Form1
    ' Form Controls: Label Label1, TextBox TextBox1, Button Button1, Button Button2, Label Label2
 
    Private output As Integer
 
    Private Sub CalculateProc(n As Integer)
        output = n * 2
    End Sub
 
    Private Function CalculateFn(n As Integer) As Integer
        Return n * 3
    End Function
 
    Private Sub Button1_Click(sender As System.Object, e As System.EventArgs) Handles Button1.Click
        Try
            CalculateProc(TextBox1.Text)            ' This calls the procedure CalculateProc using TextBox1.Text as a parameter
            Label2.Text = "Output: " & output       ' This assigns output to Label2.Text
        Catch ex As InvalidCastException
            Label2.Text = "Error: Invalid input."
        End Try
    End Sub
 
    Private Sub Button2_Click(sender As System.Object, e As System.EventArgs) Handles Button2.Click
        Try
            Label2.Text = "Output: " & CalculateFn(TextBox1.Text)
        Catch ex As Exception
            Label2.Text = "Error: Invalid input."
        End Try
    End Sub
End Class