1. VBA & Excel Barry L. Nelson IEMS 465 Fall Quarter 2003

2. VBA Is a significant subset of the stand-alone Visual Basic programming language It is integrated into Microsoft Office applications (and others, like Arena) It is the macro language of Excel You can add –Forms for dialog boxes with user –Classes for object definitions –Modules containing procedures

3. Accessing VBA in Excel Tools  Macros  Visual Basic Editor Enter VBA through the navigation buttons in the top toolbars VBA Design Mode Visual Basic Editor Design mode is the time during which no code from the project is running and events from Excel or project will not execute. You can leave design mode by executing a macro or using the Immediate window.

4. VB Edit Window Project Explorer Property Inspector Code Window Edit Window Options

5. Variables Declare by Dim Better to use Data Types: Dim amount As Double Dim year As Integer Dim name As String Other data types: Boolean, Byte, Currency, Date Default (no type) is Variant

6. Variable (cont’d.) % - integer& - long integer ! - single# - double @ currency$ - string anIntegerValue% =3, aString$ = "hallo" Can modify with scope (outside procedure) Private I As Integer Public billsPaid As Currency Make values permanent Static yourName As String Multiple variables Private test, amount, J As Integer

7. Constants [Public|Private] Const constantName [As type] = expression Public Const PI = 3.1, NumPLANETS = 9 Const PI2 = PI * 2 Const RELEASE = #1/1/99/#

8. Control Structures Decision If anyDate < Now Then anyDate = Now If anyDate < Now Then anyDate = Now End If If … Then … Else

9. Decisions (cont’d.) If Index = 0 Then CopyActiveControl ClearActiveControl Else If Index = 1 Then CopyActiveControl Else If Index = 2 Then ClearActiveControl Else PasteActive Control End If

10. Decisions (cont’d.) Select Case Index Case 0 CopyActiveControl ClearActiveControl Case 1 CopyActiveControl Case 2 ClearActiveControl Case 3 PasteActive Control Case Else frmFind.Show End Select

11. Loops/Iterations Do … Loop Do While condition statements Loop Do statements Loop While condition

12. Loops (cont’d.) For … Next For counter = start To end [Step increment] statements Next counter For Each … Next For Each element In group statements Next element

13. Exiting Control Structures For counter = start To end [Step increment] [statement block] [Exit For] [statement block] Next [counter [, counter][, …]] Do [ {While|Until} condition] [statement block] [Exit Do] [statement block] Loop

14. Exiting (cont’d.) Can also exit from a procedure: Exit Sub

15. Code Modules Excel Objects (ThisWorkbook, Sheet#) Modules –Typically we put our code here –A Module is a collection of Subs and Functions –Insert  Module Class Modules User Forms

16. Procedures Sub (routines) –no value returned –Called without parenthesis mySub param1, param2 –Called with parenthesis Call mySub(param1, param2) Functions –value returned –assign return value to function name

17. Arguments for Procedures Pass by Reference (default) sub stuff(item As String) ‘or sub stuff(ByRef item As String) … stuff(“car”) Pass by Value (must be declared) sub stuff(ByVal item As String) Note that arguments must be formally declared (as must the return type of functions)

18. Some Useful Code The following are some pieces of code that are useful for doing VBA with Excel. See the code on the course web site for other examples.

19. Finding/Creating a Sheet Dim found As Boolean Dim sheetNext As Worksheet ' Set up mySheet sheet for output found = False For Each sheetNext In Worksheets If sheetNext.Name = “mySheet" Then found = True Exit For End If Next sheetNext If found = True Then Worksheets(“mySheet").Select ActiveSheet.UsedRange.Clear Else Worksheets.Add ActiveSheet.Name = “mySheet" End If

20. Writing to a Sheet Put the absolute value of the variable Fudge in row 2, column 20 of the Sheet named mySheet. Worksheets(“mySheet”).Cells(2,20) = VBA.Abs(Fudge)

21. Use an Excel Function VBA has a limited number of built-in functions You can access any Excel worksheet function. This example uses the Excel Max function W = WorksheetFunction.Max(0, W + S - a)

22. Running the Code Perhaps the easiest way to run the code is to place your cursor in the module you want to run and press the Run Sub/UserForm button. Your modules will as appear as Macros that can be run from Excel under Tools  Macros  Macros…

23. Finishing Up Explore what is available in the IEMS 465 code Exercise: Write a Sub that inserts a worksheet named “Count” into the Workbook, then writes the numbers 1,2,…,10 in the first row, the first ten columns. Use a loop to do this.