Calling Sub and Function Procedures

To call a Sub procedure from another procedure, type the name of the procedure and include values for any required arguments. The Call statement is not required, but if you use it, you must enclose any arguments in parentheses.

You can use a Sub procedure to organize other procedures so they are easier to understand and debug. In the following example, the Sub procedure Main calls the Sub procedure MultiBeep, passing the value 56 for its argument. After MultiBeep runs, control returns to Main, and Main calls the Sub procedure Message. Message displays a message box; when the user clicks OK, control returns to Main, and Main finishes.

Sub Main()
    MultiBeep 56
    Message
End Sub

Sub MultiBeep(numbeeps)
    For counter = 1 To numbeeps
        Beep
    Next counter
End Sub

Sub Message()
    MsgBox "Time to take a break!"
End Sub

Calling Sub Procedures with More than One Argument

The following example shows two ways to call a Sub procedure with more than one argument. The second time HouseCalc is called, parentheses are required around the arguments because the Call statement is used.

Sub Main()
    HouseCalc 99800, 43100
    Call HouseCalc(380950, 49500)
End Sub

Sub HouseCalc(price As Single, wage As Single)
    If 2.5 * wage <= 0.8 * price Then
        MsgBox "You cannot afford this house."
    Else
        MsgBox "This house is affordable."
    End If
End Sub

Using Parentheses when Calling Function Procedures

To use the return value of a function, assign the function to a variable and enclose the arguments in parentheses, as shown in the following example.

Answer3 = MsgBox("Are you happy with your salary?", 4, "Question 3")

If you're not interested in the return value of a function, you can call a function the same way you call a Sub procedure. Omit the parentheses, list the arguments, and do not assign the function to a variable, as shown in the following example.

MsgBox "Task Completed!", 0, "Task Box"

Caution   If you include parentheses in the preceding example, the statement causes a syntax error.

Passing Named Arguments

A statement in a Sub or Function procedure can pass values to called procedures using named arguments. You can list named arguments in any order. A named argument consists of the name of the argument followed by a colon and an equal sign (:=), and the value assigned to the argument.

The following example calls the MsgBox function using named arguments with no return value.

MsgBox Title:="Task Box", Prompt:="Task Completed!"

The following example calls the MsgBox function using named arguments. The return value is assigned to the variable answer3.

answer3 = MsgBox(Title:="Question 3", _
Prompt:="Are you happy with your salary?", Buttons:=4)