EXCEL VBA PROGRAMMINGPART 1

MORTEZA NOSHAD

MSPRO.NOSHAD@GMAIL.COM

0912 - 84 98 775

WHAT CAN YOU DO WITH VBA?

Inserting a bunch of text

Automating a task you perform frequently

Automating repetitive operations

Creating a custom command

Creating a custom button

Developing new worksheet functions

Creating custom add-ins for Excel

Creating complete, macro-driven applications

ADVANTAGES AND DISADVANTAGES OF VBA

Excel always executes the task in exactly the same way. (In most cases, consistency is a good thing.)Excel performs the task much faster than you can do it manually (unless, of course, you’re Clark Kent).you’re a good macro programmer, Excel always performs the task without errors (which probably can’t be said about you or me)If you set things up properly, someone who doesn’t know anything about Excel can perform the taskYou can do things in Excel that are otherwise impossible — which can make you a very popular person around the officeFor 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 ADVANTAGES

ADVANTAGES AND 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

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 transforms 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 will always work correctly under all circumstances. Welcome to the world of debugging and, if others are using your macros, technical support

VBA is a moving target. As you know, Microsoft is continually upgrading Excel. Even though Microsoft puts great effort into compatibility between versions, you may discover that the VBA code you’ve written doesn’t work properly with older versions or with a future version of Excel

VBA DISADVANTAGES

VBA IN A NUTSHELLYou perform actions in VBA by writing (or recording) code in a VBA module

A VBA module consists of Sub procedures

A VBA module can also have Function procedures

VBA manipulates objects

Objects are arranged in a hierarchy

Objects of the same type form a collectionYou refer to an object by specifying its position in the object hierarchy, using a dot (a.k.a., a period) as a separatorIf you omit specific references, Excel uses the active objects

Objects have properties

VBA IN A NUTSHELL

You refer to a property of an object by combining the object name with the property name, separated by a dot

You can assign values to variables

Objects have methods

You specify a method by combining the object with the method, separated by a dot

VBA includes all the constructs of modern programming languages, including variables, arrays, and looping

MACRO

Create your first macro

Use relative references

Macro shortcut key-Place macro

Examining macro

How Excel Executes Statements

Saving workbooks that contain macros

Understanding macro security

VISUAL BASIC EDITOR

Working with the Project Explorer

Working with a Code Window

Getting VBA code into a module

Enter the code directly.

Use the Excel macro recorder to record your actions and convert them to VBA code

Copy the code from one module and paste it into another.

Customizing the VBA Environment

SUBS VERSUS FUNCTIONS

A Sub procedure is a group of VBA statements that performs an action (or actions) with Excel.

A Function procedure is a group of VBA statements that performs a calculation and returns a single value.

NAMING SUBS AND FUNCTIONSYou can use letters, numbers, and some punctuation characters, but the first character must be a letter.

You can’t use any spaces or periods in the name.

VBA does not distinguish between uppercase and lowercase letters.

You can’t embed any of the following characters in a name: #, $, %, &, @,^, *, or !.

If you write a Function procedure for use in a formula, make sure the name does not look like a cell address (for example, AC12).

Names can be no longer than 255 characters. (Of course, you would never make a procedure name this long.)Ideally, a procedure’s name should describe the routine’s purpose. A good practice is to create a name by combining a verb and a noun — for example, ProcessData, PrintReport, Sort_Array, or CheckFilename

EXCECUTING SUB PROCEDURESWith the Run➪Run sub/UserForm command (in the VBE) & F5 key.

From Excel’s Macro dialog box. You open this box by choosing Developer➪Code➪Macros). Or you can press the Alt+F8 shortcut key. require an argument.

Using the Ctrl+key shortcut assigned to the Sub procedure

Clicking a button or a shape on a worksheet

From another Sub procedure that you write

From a button on the Quick Access Toolbar

From a custom item on the ribbon you develop

Automatically, when you open or close a workbook

When an event occurs

From the Immediate window in the VBE

EXECUTING FUNCTION PROCEDURES

By calling the function from another Sub procedure or Function procedure

By using the function in a worksheet formula

COMMENTS

A comment is the simplest type of VBA statement. Because VBA

ignores these statements, they can consist of anything you want. You

can insert a comment to remind yourself why you did something or

to clarify some particularly elegant code you wrote. Use comments

liberally and extensively to describe what the code does (which isn’t

always obvious by reading the code itself). Often, code that makes

perfect sense today mystifies you tomorrow

COMMENTS

When testing a procedure, you may want to remove some

statements temporarily. Rather than delete the statements, you can

convert them to comments. Then when testing is completed, convert

the comments back to statements. In the VBE, choose

view➪Toolbars➪Edit to display the Edit toolbar. To convert a block

of statements to comments, select the statements and click the

Comment Block button. To remove the apostrophes, select the

statements and click the Uncomment Block button.

COMMENTS• The following tips can help you make effective use of comments:• Briefly describe the purpose of each Sub or Function procedure• you write.• Use comments to keep track of changes you make to a procedure.• Use a comment to indicate that you’re using a function or a construct• in an unusual or nonstandard manner.• Use comments to describe the variables you use, especially if you

don’t use meaningful variable names.• Use a comment to describe any workarounds you develop to

overcome bugs in Excel.• Write comments as you develop code, instead of saving the task for

a final step.

UNDERSTANDING VARIABLESA variable is simply a named storage location in your computer’s memory. You have lots of flexibility in naming your variables, so make the variable names as descriptive as possible. You assign a value to a variable by using the equal sign operator.

You can use letters, numbers, and some punctuation characters, but the first character must be a letter.You cannot use any spaces or periods in a variable name.VBA does not distinguish between uppercase and lowercase letters.You cannot use the following characters in a variable name: #, $, %, &, or !.Variable names can be no longer than 255 characters.

UNDERSTANDING VARIABLESwear yourself out typing the entire name of a variable. Just

type the first two or three characters and then hit Control+Space. The VBE will either complete the entry for you or — if the choice is ambiguous — show you a pick list to select from. In fact, this slick trick works with reserved words too.

has many reserved words that you can’t use for variable names or procedure names. These include words such as Sub, Dim, With, End, and For. If you attempt to use one of these words as a variable, you may get a compile error (your code won’t run). So, if an assignment statement produces an error message, double-check and make sure that the variable name isn’t a reserved word.

WHAT ARE VBA’S DATA TYPES?

DECLARING AND SCOPING VARIABLES

WORKING WITH CONSTANTS

WORKING WITH OPERATORS

WORKING WITH ARRAYS

INTRODUCING THE EXCEL OBJECT MODEL

INTRODUCING THE EXCEL OBJECT MODEL

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COLLECTIONS OF OBJECTS

REFERRING TO OBJECTS

In this case, the number is not in quotation marks. Bottom line? If you refer to an object by using its name, use quotation marks. If you refer to an object by using its index number, use a plain number without quotation marks.

NAVIGATING THROUGH THE HIERARCHY

WORKING WITH RANGE OBJECTS

WORKING WITH RANGE OBJECTS

WORKING WITH RANGE OBJECTS

WORKING WITH RANGE OBJECTS

USING VBA AND WORKSHEET FUNCTIONS

VBA FUNCTIONS THAT DO MORE THAN RETURN A VALUE