About Brandon Drake Expertise I can answer questions regarding the Graphics object, file access, general optimization, printing (on paper), user controls, program mathematics, the registry, creating macros, processes, and fundamental or basic questions. I have made a few asp.net pages but I do not know the language extensively. I have not done much work with databases but I have created my own database systems.
Experience I have been programming with visual basic for 6 years. In all I have written programs in about 8 programming languages, although, I only know about 3 well. I have written a few applications but mainly I like to write programs for fun.
Expert: Brandon Drake Date: 5/23/2006 Subject: boolean function
Question Dear Sir, Thanks for your kindly reply, still have doubt..Thanks.. If Not ValidateData() Then Return so you mean - if Not [False] , then will execute the Return, right? But what is the actual statement that shows - if [True] only can execute the Return? I mean why is it - if [False] cannnot execute Return? ************************************************** Dear Sir, Need your explaination to understand the following Boolean function. Thanks in advance. ********************************************************* Private Sub btnHire_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles btnHire.Click If Not ValidateData() Then Return End If Select Case cboEmployeeType.SelectedIndex Case -1 Exit Sub Case 0 HireFullTimeEmployee() End Select End Sub Private Function ValidateData() As Boolean Dim dataInValid As Boolean = True If Not IsDate(txtHireDate.Text) Then MsgBox( Hire Date must be a date in the format MM/DD/YY. , _ MsgBoxStyle.Exclamation, Me.Text) dataInValid = False End If Return (dataInValid) End Function ********************************************************** Let say I hit the btnHire, it will execute the first line - If Not ValidateData() Then. Afterthat it will go to ValidateData function. Let say the txtHireDate.Text is in invalid format, so a message prompt and dataInValid=False. Finally Return(dataInValid) which is False and again back to btnHire. So what I don t understand is : Once back to first line - If Not ValidateData() Then , what is the actual return value of this ValidateData()? This line means what ?
Answer callisto,
Sorry I clicked a wrong button and sent you another message--I can answer your question.
if [False] cannot execute the Return because that would mean the data is valid. The Return is there so that if invalid data is used then the function won't do anything. If there is valid data the function will continue to execute. The only time the function should return at the if, is if there is invalid data.
