Use of Functions

[bplus]

To illustrate further the difference between a Function and an equivalent Sub:

Code: (Select All)

nNames = 5
Dim names$(1 To nNames)
names$(1) = "PhilOfPerth"
names$(2) = "bplus"
names$(3) = "ahenry3068"
names$(4) = "SMcNeill"
names$(5) = "Who am I?"
For i = 1 To nNames

    ' using a function only takes one line to report results
    Print "Function last letter for "; names$(i); " is "; LastLetter$(names$(i))

    ' using a sub like a Function usually requires a call to it then another line to report results
    lastLetter names$(i), ll$
    Print "Sub last letter for "; names$(i); " is "; ll$
    Print
Next

Function LastLetter$ (mystring$)
    LastLetter$ = Mid$(mystring$, Len(mystring$), 1)
End Function

Sub lastLetter (mystring$, myLastLetter$)
    myLastLetter$ = Mid$(mystring$, Len(mystring$), 1)
End Sub

Phil: "With a Sub I can change several variables at the same time."

If you need variables changed then yeah by all means use a Sub.
Functions do a job of processing some information and returning a single result like a formula Area = Pi*R^2
Function AreaCircle(R)
AreaCircle = _Pi * R^2
End Function

The advantage of Functions is they wont change their arguments unless you tell them to.