Based on this characteristic of the procedures of a module having access to global variables of the same program, you can declare such variables and initialize or modify them in any procedure of the same code file.
So far, to use a value in a procedure, we had to declare it. In some cases, a procedure may need an external value in order to carry its assignment. A value that is supplied to a procedure is called an argument. When creating a procedure that will use an external value, declare the argument that represents that value between the parentheses of the procedure. For a sub procedure, the syntax you use would be: Sub ProcedureName(Argument)
End Sub
If you are creating a function, the syntax would be: Function ProcedureName(Argument) As DataType
Function Sub
The argument must be declared as a normal variable, omitting the Dim keyword. Here is an example that creates a function that takes a string as argument: Function CalculatePayroll(strName As String) As Double
Function Sub
A certain procedure can take more than one argument. In this case, in the parentheses of the procedure, separate the arguments with a comma. Here is an example of a sub procedure that takes two arguments: Sub EvaluateInvoice(EmplName As String, HourlySalary As Currency)
End Sub
In the body of a procedure that takes one or more arguments, use the argument(s) as you see fit as if they were locally declared variables. For example, you can involve them with values inside of the procedure. You can also exclusively use the values of the arguments to perform the assignment.
To call a procedure that takes an argument, type its name and a space, followed by a value for each argument between parentheses. The value provided for an argument is also called a parameter. If there is more than one argument, separate them with a comma. Here is an example: Module Exercise
Private Function GetFullName$(strFirst As String, _
strLast As String)
Dim FName As String
FName = strFirst & " " & strLast
GetFullName = FName
End Function
Public Function Main() As Integer
Dim FirstName, LastName As String
Dim FullName As String
Dim ComputerLanguage As String = "Visual Basic"
FirstName = inputbox("Enter First Name: ")
LastName = inputbox("Enter Last Name: ")
FullName = GetFullName(FirstName, LastName)
msgbox("Hello, " & FullName)
Welcome(ComputerLanguage)
Return 0
End Function
Sub Welcome(ByVal strLanguage As String)
msgbox("Welcome to the wonderful world of " & strLanguage)
End Sub
End Module
As mentioned previously, you can also use the Call keyword to call a procedure. When you call a procedure that takes more than one argument, you must provide the values of the arguments in the exact order they are listed inside of the parentheses of the function. Fortunately, you do not have to. If you know the names of the arguments, you can type them in any order and provide a value for each. To do that, on the right side of each argument, type the := operator followed by the desired value for the argument. Here is an example: Public Module Exercise
Private Function GetFullName$(MI As String, _
LastName As String, _
FirstName As String)
GetFullName = FirstName & " " & MI & " " & LastName
End Function
Public Function Main() As Integer
Dim FullName As String
Dim ComputerLanguage As String = "VBasic"
FullName = GetFullName(LastName:="Roberts", FirstName:="Alan", MI:="R.")
MsgBox("Hello " & FullName)
Call Welcome(ComputerLanguage)
Return 0
End Function
Private Sub Welcome(ByVal strLanguage As String)
MsgBox("Welcome to the wonderful world of " & strLanguage)
End Sub
End Module
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Practical Learning:
Using Global Variables
