Global variables...good or bad

[sjn78]

I have nearly finished my program and I am now looking over it to clean up any rubbish and trying to make things runs a little quicker.

I have a few global variables that hold options for the program. These options are read in when the program launches.

Would it be better to only read the options in when they are required or to keep it the way i have it.

I guess having global variables will use more memory than if I didn't have them.

The second part of my quiestion is this. I have a few functions in a module to retrieve the ID of a person in the databse. I would like to turn this into a class but am a little unsure on how to do it.

This is what I have in the module.

Function GetNameID(ByVal fname As String, ByVal lname As String)
    Dim nameid As Integer

    If fname = "NULL" Or lname = "NULL" Then
      Return 0
    End If

    Dim sql As String = "SELECT ID, Surname, Firstname FROM Contacts " & _ 
       "WHERE Surname = '" & lname & "' AND Firstname = '" & fname & "'"
    Dim objDsName = New DataSet()
    Dim objDaName = New OleDbDataAdapter(sql, cnstring)
    objDaName.Fill(objDsName, "TempName")

    For Each objrow In objDsName.tables(0).rows
      nameid = objrow("ID")
    Next

    objDsName.dispose()
    objDaName.dispose()

    Return nameid

  End Function

Now how would i implement this into a class.

Thanks for any help or advice

Steve

 

[mutant]

Instead of putting your global variables and functions in a module you could put all of those in a class and make those variables and methods shared. This means that they do not need an instance of a class to be used.