For Dummies Excel VBA Programming, 2nd Edition
Contents
1. VBA procedure or even use it as a function in a worksheet formula An example of a Function procedure named AddTwo follows This Function accepts two numbers called arguments and returns the sum of those values Function AddTwo argl arg2 AddTwo argl arg2 End Function A Function procedure that doesn t work correctly is said to be dysfunctional VBA manipulates objects Excel provides dozens and dozens of objects that you can manipulate Examples of objects include a workbook a worksheet a cell range a chart and a shape You have many more objects at your disposal and you can manipulate them by using VBA code 1 Objects are arranged in a hierarchy Objects can act as containers for other objects At the top of the object hierarchy is Excel Excel itself is an object called Application The Application object contains other objects such as Workbook objects and Add In objects The Workbook object can contain other objects such as Worksheet objects and Chart Chapter 1 WhatIsVBA 19 objects A Worksheet object can contain objects such as Range objects and PivotTable objects The term object model refers to the arrangement of these objects Object model mavens can find out more in Chapter 4 1 Objects of the same type form a collection For example the Worksheets collection consists of all the worksheets in a particular workbook The Charts collection consists of all Chart objects in a work book Collections are t2. Chapter 1 What Is VBA In This Chapter Gaining a conceptual overview of VBA Finding out what you can do with VBA Discovering the advantages and disadvantages of using VBA Taking a mini lesson on the history of Excel f you re anxious to jump into VBA programming hold your horses This chapter is completely devoid of any hands on training material It does however contain some essential background information that assists you in becoming an Excel programmer In other words this chapter paves the way for everything else that follows and gives you a feel for how Excel program ming fits into the overall scheme of the universe It s not as boring as you might think Okay So What Is VBA VBA which stands for Visual Basic for Applications is a programming lan guage developed by Microsoft you know the company that tries to get you to buy a new version of Windows every few years Excel along with the other members of Microsoft Office includes the VBA language at no extra charge In a nutshell VBA is the tool that people like you and me use to develop pro grams that control Excel Imagine an intelligent robot that knows all about Excel This robot can read instructions and it can also operate Excel very fast and accurately When you want the robot to do something in Excel you write up a set of robot instruc tions by using special codes Tell the robot to follow your instructions while you sit back and drink a glass of lem
3. eas a nice fruitcake would be lovely 1 Yadda yadda yadda The list could go on and on but I think you get the idea My point is simply that Excel is used for a wide variety of things and everyone reading this book has different needs and expectations regarding Excel One thing virtually every reader has in common is the need to automate some aspect of Excel That dear reader is what VBA is all about For example you might create a VBA program to import some numbers and then format and print your month end sales report After developing and test ing the program you can execute the macro with a single command causing Excel to automatically perform many time consuming procedures Rather than struggle through a tedious sequence of commands you can grab a cup of joe and let your computer do the work which is how it s supposed to be right Chapter 1 WhatIsvBA 15 In the following sections I briefly describe some common uses for VBA macros One or two of these may push your button Inserting a bunch of text If you often need to enter your company name address and phone number in your worksheets you can create a macro to do the typing for you You can extend this concept as far as you like For example you might develop a macro that automatically types a list of all salespeople who work for your company Automating a task you perform frequently Assume you re a sales manager and you need to prepare a m
4. ew file format which previous Excel versions cannot open Occasionally I run into someone who still uses this version 1 Excel 2000 This version s numbering scheme jumped to four digits Excel 2000 also known as Excel 9 made its public debut in June 1999 It includes only a few enhancements from a programmer s perspective with most enhancements being for users particularly online users With Excel 2000 came the option to digitally sign macros thus enabling you to guarantee that the code delivered to your users is truly yours Excel 2000 still has a modest number of users 1 Excel 2002 This version also known as Excel 10 or Excel XP appeared in late 2001 Perhaps this version s most significant feature is the ability to recover your work when Excel crashes This is also the first version to use copy protection known as product activation Excel 2003 Of all the Excel upgrades I ve ever seen and I ve seen them all Excel 2003 has the fewest new features In other words most hard core Excel users including yours truly were very disappointed with Excel 2003 Yet people still bought it I think these were the folks moving up from a pre Excel 2002 version As I write this Excel 2003 is probably the most commonly used version 1 Excel 2007 Excel 2007 signaled the beginning of a new era Excel 2007 dumped the old menu and toolbar interface and introduced the Ribbon It also allows much larger worksheets more t
5. han a million rows v Excel 2010 The latest and without a doubt the greatest Microsoft outdid its corporate self with this version This version has some slick new features such as sparkline graphics and it also performs quite a bit better in some areas And if you need really really huge workbooks you can install the 64 bit version 21 22 Part I Introducing VBA MBER KO amp This book is written for Excel 2007 and Excel 2010 so if you don t have one of those versions you run the risk of getting confused in a few places So what s the point of this mini history lesson If you plan to distribute your Excel VBA files to other users it s vitally important that you understand which version of Excel they use People using an older version won t be able to take advantage of features introduced in later versions For example if you write VBA code that references cell XFD1048576 the last cell in a workbook those who use a version prior to Excel 2007 will get an error because those pre Excel 2007 worksheets only had 65 536 rows and 255 columns the last cell is I1V65536 Excel 2007 and Excel 2010 also have some new objects methods and properties If you use these in your code users with an older version of Excel will get an error when they run your macro and you ll get the blame However Microsoft has made available an Office Compatibility Pack which allows users of Excel 2003 and Excel XP to open and save
6. hemselves objects Y You refer to an object by specifying its position in the object hierar chy using a dot that is a period as a separator For example you can refer to the workbook Book1 xlsx as Application Workbooks Book1 xlsx This refers to the workbook Book1 xlsx in the Workbooks collection The Workbooks collection is contained in the Application object that is Excel Extending this to another level you can refer to Sheet1 in Book xlsx as Application Workbooks Book1 xlsx _ Worksheets Sheet1 As shown in the following example you can take this to still another level and refer to a specific cell in this case cell Al Application Workbooks Book1 xlsx Worksheets Sheet1 Range A1 If you omit specific references Excel uses the active objects If Book1 xlsx is the active workbook you can simplify the preceding reference as follows Worksheets Sheet1 Range Al1 If you know that Sheet is the active sheet you can simplify the refer ence even more Range A1 Objects have properties You can think of a property as a setting for an object For example a Range object has such properties as Value and Address A Chart object has such properties as HasTitle and Type You can use VBA to determine object properties and also to change properties You refer to a property of an object by combining the object name with the property name separated by a dot For example you can refer t
7. ll always work correctly under all circum stances Welcome to the world of debugging and if others are using your macros technical support 1 VBA is a moving target As you know Microsoft is continually upgrad ing Excel Even though Microsoft puts great effort into compatibility between versions you may discover that VBA code you ve written doesn t work properly with older versions or with a future version of Excel 18 Part I Introducing VBA VBA in a Nutshell Just to let you know what you re in for I ve prepared a quick and dirty sum mary of what VBA is all about Of course I describe all this stuff in semi excruciating detail later in the book You perform actions in VBA by writing or recording code in a VBA module You view and edit VBA modules by using the Visual Basic Editor VBE 1 A VBA module consists of Sub procedures A Sub procedure has noth ing to do with underwater vessels or tasty sandwiches Rather it s a chunk of computer code that performs some action on or with objects discussed in a moment The following example shows a simple Sub procedure called AddEmUp This amazing program displays the result of 1 plus 1 Sub AddEmUp Summ i sp i MsgBox The answer is amp Sum End Sub A Sub procedure that doesn t perform properly is said to be substandard A VBA module can also have Function procedures A Function proce dure returns a single value You can call it from another
8. o the Value property in cell Al on Sheet1 as follows Worksheets Sheet1 Range A1 Value 20 Part I Introducing VBA You can assign values to variables A variable is a named element that stores information You can use variables in your VBA code to store such things as values text or property settings To assign the value in cell Al on Sheet1 to a variable called nterest use the following VBA statement Interest Worksheets Sheet1 Range A1 Value 1 Objects have methods A method is an action Excel performs with an object For example one of the methods for a Range object is ClearContents This aptly named method clears the contents of the range You specify a method by combining the object with the method sepa rated by a dot For example the following statement clears the contents of cell Al Worksheets Sheet1 Range Al ClearContents 1 VBA includes all the constructs of modern programming languages including arrays and looping In other words if you re willing to spend a little time mastering the ropes you can write code that does some incredible things Believe it or not the preceding list pretty much describes VBA in a nutshell Now you just have to find out the details That s why this book has more pages An Excursion into Versions If you plan to develop VBA macros you should have some understanding of Excel s history I know you weren t expecting a history lesson when
9. onade That s kind of what VBA is all about a code language for robots Note however that Excel does not come with a robot or lemonade 14 Part I Introducing VBA Re S Tlp A few words about terminology Excel programming terminology can be a bit confusing For example VBA is a programming language but it also serves as a macro lan guage What do you call something written in VBA and executed in Excel Is it a macro or is it a program Excel s Help system often refers to VBA procedures as macros so use that ter minology But also call this stuff a program use the term automate throughout this book This term means that a series of steps are Here are just a few examples 1 Analyzing scientific data 1 Budgeting and forecasting completed automatically For example if you write a macro that adds color to some cells prints the worksheet and then removes the color you have automated those three steps By the way macro does not stand for Messy And Confusing Repeated Operation Rather it comes from the Greek makros which means large which also describes your paycheck after you become an expert macro programmer What Can Vou Do with VBA You re probably aware that people use Excel for thousands of different tasks Creating invoices and other forms 1 Developing charts from data Keeping lists of things such as customers names students grades or holiday gift id
10. onth end sales report to keep your boss happy If the task is straightforward you can develop a VBA program to do it for you Your boss will be impressed by the consistently high quality of your reports and you ll be promoted to a new job for which you are highly unqualified Automating repetitive operations If you need to perform the same action on say 12 different Excel workbooks you can record a macro while you perform the task on the first workbook and then let the macro repeat your action on the other workbooks The nice thing about this is that Excel never complains about being bored Excel s macro recorder is similar to recording live action on a video recorder But it doesn t require a camera and the battery never needs to be recharged Creating a custom command Do you often issue the same sequence of Excel menu commands If so save yourself a few seconds by developing a macro that combines these com mands into a single custom command which you can execute with a single keystroke or button click You probably won t save that much time but you ll probably be more accurate And the guy in the next cubicle will be really impressed 16 Part I Introducing VBA Creating a custom button You can customize your Quick Access toolbar with your own buttons that execute the macros you write Office workers tend to be very impressed by buttons that perform magic If you re using Excel 2010 you can even add buttons to
11. t Excel carries out Automating a task by using VBA offers several advantages 1 Excel always executes the task in exactly the same way In most cases consistency is a good thing 1 Excel performs the task much faster than you can do it manually unless of course you re Clark Kent 1 If you re a good macro programmer Excel always performs the task without errors which probably can t be said about you or me 1 If you set things up properly someone who doesn t know anything about Excel can perform the task You can do things in Excel that are otherwise impossible which can make you a very popular person around the office Y For long time consuming tasks you don t have to sit in front of your computer and get bored Excel does the work while you hang out at the water cooler VBA disadvantages It s only fair that I give equal time to listing the disadvantages or potential disadvantages of VBA You have to know how to write programs in VBA but that s why you bought this book right Fortunately it s not as difficult as you might expect 1 Other people who need to use your VBA programs must have their own copies of Excel It would be nice if you could press a button that trans forms your Excel VBA application into a stand alone program but that isn t possible and probably never will be Sometimes things go wrong In other words you can t blindly assume that your VBA program wi
12. the Ribbon something that s off limits in Excel 2007 Developing new worksheet functions Although Excel includes numerous built in functions such as SUM and AVERAGE you can create custom worksheet functions that can greatly simplify your formulas I guarantee you ll be surprised by how easy this is Ad show you how to do this in Chapter 20 Even better the Insert Function dialog box displays your custom functions making them appear built in Very snazzy stuff Creating complete macro driven applications If you re willing to spend some time you can use VBA to create large scale applications complete with a custom Ribbon tab dialog boxes on screen help and lots of other accoutrements This book doesn t go quite that far but I m just telling you this to impress you with how powerful VBA really is Creating custom add ins for Excel You re probably familiar with some of the add ins that ship with Excel For example the Analysis ToolPak is a popular add in You can use VBA to develop your own special purpose add ins I developed my Power Utility Pak add in by using only VBA and people all around the world pay me real money so they can use it Advantages and Disadvantages of VBA In this section I briefly describe the good things about VBA and I also explore its darker side Chapter 1 Whatis VBA 17 VBA advantages You can automate almost anything you do in Excel To do so you write instructions tha
13. workbooks in the new file format This product which is free by the way doesn t give these older versions the new features It just lets them open and save files in the Excel 2007 2010 file format
14. you picked up this book but bear with me This is important stuff that might make you a hit at the next nerd party Here are all the major Excel for Windows versions that have seen the light of day along with a few words about how they handle macros 1 Excel 2 The original version of Excel for Windows was called Version 2 rather than 1 so that it would correspond to the Macintosh version Excel 2 first appeared in 1987 but nobody uses it anymore so you can pretty much forget that it ever existed 1 Excel 3 Released in late 1990 this version features the XLM macro lan guage Nobody uses this version either Chapter 1 What Is VBA Excel 4 This version hit the streets in early 1992 It also uses the XLM macro language A small number of people still use this version They subscribe to the philosophy if it ain t broke don t fix it v Excel 5 This one came out in early 1994 It was the first version to use VBA but it also supports XLM Excel 5 users are becoming increasingly rare 1 Excel 95 Technically known as Excel 7 there is no Excel 6 this version began shipping in the summer of 1995 It s a 32 bit version and requires Windows 95 or Windows NT It has a few VBA enhancements and it sup ports the XLM language 1 Excel 97 This version also known as Excel 8 was born in January 1997 It has many enhancements and it features an entirely new inter face for programming VBA macros Excel 97 also uses a n
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