Page 194 - Open Soource Technologies 304.indd

Event Driven Programming

Private Sub btnCalculate_Click(...) Handles btnCalculate.Click
‘Calculate the length of the hypotenuse of a right triangle
Dim a, b As Double
a = CDbl(txtSideOne.Text)
b = CDbl(txtSideTwo.Text)
txtHyp.Text = CStr(Hypotenuse(a, b))
End Sub
function Hypotenuse(ByVal a As Double, ByVal b As Double) As Double
‘Calculate the hypotenuse of a right triangle
‘having sides of lengths a and b
Return Math.Sqrt(a ^ 2 + b ^ 2)
End function
[Run, type 3 and 4 into the text boxes, and then click the button.]

8.3 User-Defined Function Having No Parameters

Function, like sub function, need not have any parameters.

1: The following program uses a parameterless function.

Private Sub btnDisplay_Click(...) Handles btnDisplay.Click
‘Request and display a saying
txtBox.Text = Saying()
End Sub
function Saying() As String
‘Retrieve a saying from the user
Return InputBox(“What is your favorite saying?”)

188 LOVELY PROFESSIONAL UNIVERSITY