Lesson 17: Creating Functions in VB2019

Public Class Form1
    Private Function BMI(Height As Single, weight As Single) As Double
        BMI = weight / Height ^ 2
    End Function

    Private Sub BtnCal_Click(sender As Object, e As EventArgs) Handles BtnCal.Click
        Dim h As Single, w As Single
        h = Val(TextBox1.Text)
        w = Val(TextBox2.Text)
        LblBMI.Text = BMI(h, w)
    End Sub
End Class

Public Class Form1
    Private Function FV(pv As Single, i As Single, n As Integer) As Double
        FV = pv * (1 + i / 100) ^ n
    End Function

    Private Sub BtnCal_Click(sender As Object, e As EventArgs) Handles BtnCal.Click
        Dim FutureVal As Single
        Dim PresentVal As Single
        Dim interest As Single
        Dim period As Integer
        PresentVal = TxtPV.Text
        interest = TxtInt.Text
        period = TxtN.Text
        FutureVal = FV(PresentVal, interest, period)
        LblFV.Text = Format(FutureVal, "$#,##0.00")
    End Sub
End Class

Public Class Form1
    Private Function sqroot(ByRef x As Single) As Double
        x = x ^ 0.5
        sqroot = x
    End Function

    Private Function sqroot1(ByVal y As Single) As Double
        y = y ^ 0.5
        sqroot1 = y
    End Function

    Private Sub Button1_Click(sender As Object, e As EventArgs) Handles Button1.Click
        Dim u As Single
        u = 9
        MsgBox(3 * sqroot(u), , "ByRef")
        MsgBox("Value of u is " & u, , "ByRef")
    End Sub

    Private Sub Button2_Click(sender As Object, e As EventArgs) Handles Button2.Click
        Dim u As Single
        u = 9
        MsgBox(3 * sqroot1(u), , "ByVal")
        MsgBox("Value of u is " & u, , "ByVal")
    End Sub
End Class