Things to Review Variables Procedures: Subs & Functions If…Then For…Next
Variables Just like in math, variables: Have a name Have a value Value can be changed Examples: x = 1 : debug.print x x = 2 : debug.print x
Procedures Subroutines (Subs) Can do things but not return values. Subs without arguments can be called from the Excel macro toolbar. Functions Functions return values in VBA with the form: FunctionName = SomeValue Functions can be inserted into Excel sheets from the Insert|Function menu.
If…Then If…Then has two basic forms: Statement If (x = 1) Then Debug.Print "Yes" Code Block If (x = 1) Then y = 1 Else y = -1 End If
For…Next Loops through a range of values and executes the statements in the block. For x = 1 To 10 Debug.Print x Next 1 2 3 4 5 6 7 Etc.
VBA Variable Types The most commonly used VBA types are: Boolean (True or False) Numeric Types: Integer, Double, Currency Date String Variant (holds almost anything) Object Types: Ranges, Worksheets, etc.
Objects A combination of code and data that can be treated as a unit, for example, a control, form, or application component. Each object is defined by a class. (MS) Examples: Workbooks Worksheets Charts Ranges
Declaring Variables Declaring means: Telling VBA that you are going to use it Defining the variable's type Declare variables using the Dim statement Dim MyName as String Dim MyBirthday as Date Dim BigMoney as Currency Dim wks as Worksheet
Assigning Values to Variables Most variables can simple be assigned like this: X = 5 MyName = "Bob" Objects need to be assigned using Set Set MyDataSheet = ActiveSheet Set MyChart = ActiveChart
Specific -> Generic Instead of... Range("A1") Sheets("Sheet1") Charts("Chart1") Use Selection or ActiveCell ActiveSheet ActiveChart
Collection Object Most of the VBA objects you use are parts of collections. For example: Charts: a collection of Chart objects Worksheets: a collection of Worksheet objects Collections have the following: Count: number of items in the collection Add: add an item Item: get the value of an item Remove: delete item
Collection: Example Sub AddWorksheet() Dim wks As Worksheet Set wks = Worksheets.Add MsgBox "Added: " + wks.Name End Sub
Looping Through Collections Collections are handy to use because we can easily look at each item in the collection using a "For Each" loop. For example: Sub ListWorksheets() Dim wks As Worksheet For Each wks In ActiveWorkbook.Worksheets MsgBox wks.Name Next End Sub