EXCEL WORKSHOP III INTRODUCTION TO MACROS AND VBA PROGRAMMING

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Augustus Daniels
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1 EXCEL WORKSHOP III INTRODUCTION TO MACROS AND VBA PROGRAMMING

2 TABLE OF CONTENTS 1. What is VBA? 2. Safety First! 1. Disabling and Enabling Macros 3. Getting started 1. Enabling the Developer tab 4. Basic VBA 1. Hierarchy 2. Properties & Methods 3. Variables 5. Macro Recorder

3 TABLE OF CONTENTS 6. Hello World 1. MsgBox 2. OnLoad 7. Buttons 8. Reactions 9. Arrays 10. Example: AddOneYear() to a development triangle 1. Loops / Conditional Statements 2. Custom functions

4 WHAT IS VBA? VBA stands for Visual Basic for Applications Closely related to Microsoft s Visual Basic VB is very archaic and now retired VBA an Object-based Language Similar to object-oriented languages (C++, Java) You ll see variables, for-loops, functions, etc. Excel workbooks that contain macros are.xlsm files Normal workbooks are.xlsx We use VBA to make repetitive or complex jobs easier

5 SAFETY FIRST! By default, macros are disabled with notification Potentially malicious code can run For example, endless MsgBoxes You need to enable macros when opening a.xlsm workbook Only enable macros from sources you trust Access Macro Settings: File > Options > Trust Center > Trust Center Settings > Macro Settings

6 GETTING STARTED Enable the Developer tab Right click on the ribbon > Customize ribbon > Check-mark the developer tab Open the VBA Editor Click Developer tab > Visual Basic Or use Alt+F11 The Editor is where you edit VBA modules Modules consists of Sub procedures and Function procedure

7 BASIC VBA: HIERARCHY VBA is object-based Objects include Workbooks, Worksheets, Cells, and Variables Objects are organized into a hierarchy: Application.Workbooks("Book1.xlsx") Application.Workbooks("Book1.xlsx").Worksheets("Sheet1") Application.Workbooks("Book1.xlsx").Worksheets("Sheet1").Range( A1 ) Excel uses the active objects if you omit references Range( A1 ) refers to Cell A1 on the active worksheet in the active workbook You can also access cells using column and row number Cell A2 is Cells(1,2) or Range( A2 )

8 BASIC VBA: PROPERTIES & METHODS Objects have properties Range("A1").Value 'Returns the content of Cell A1 Range("A1").Width 'Returns the width of the Cell A1 Range("A1").Font Objects have methods Range("A1").ClearContents Workbook("Book1.xlsx").Close Range("A2:A3").Copy _ 'Underscore indicates continuation to next line destination:= Range("B2") 'destination is a parameter of the Copy method

9 BASIC VBA: VARIABLES Declaring a variable using the keywords Dim and as Dim myint as Integer 'Allocates 2 bytes of memory for an Integer myint = 100 'Sets the value of the variable Other commonly used data types include Double (8 bytes) Used for floating-point numbers (decimals) Fixed-length String (Size depends on number of characters) Used for text Dim mystring As String * stringlength Variable-length String (10 more bytes than a Fixed-length String) Dim mystring As String Boolean (2 bytes ) True (-1) or False (0) Variant (16 bytes) Can store any kind of data. Slower to process and makes code hard to read.

10 THE IMMEDIATE WINDOW Very useful feature in the VBA Editor Open with Ctrl+G or View > Immediate Window You can ask questions in the Immediate Window?Worksheets.Count?Range("B2").Value Debug.Print is useful when you are debugging Public Sub PrintValue() Debug.Print "Hello" 'Prints to the immediate window Debug.Print x 'Prints the value of the variable x End Sub

11 RECORDING MACROS A lot of people learn to code in VBA by recording actions in Excel and reading the code for those actions. Step 1: Start recording Developer > Code > Record Macro Step 2: Do stuff in your workbook Step 3: Stop recording Developer > Code > Stop Recording Step 4: Read the code in the Editor Developer > Code > Visual Basic (or Alt+F11)

12 RECORDING MACROS: EXAMPLE You have data on ALL Major League Baseball teams performance from the past decades We ask: How has the win-percentage of 1 st -place teams in the NL West Division changed over the years? Generate a linear regression line. 1. Go to the sheet Using Macro Recorder 2. Start recording: Developer > Code > Record Macro 3. Activate filtering: Data > Sort & Filter > Filter 4. Filter Column D for NL West 5. Filter Column K for 1 st Place Finishes 6. Select Columns B (Year) and I (Win Percentage) 7. Insert > Scatterplot 8. Right-click the plus-sign (+) for Chart Elements, then add Trendline 9. Go to More Options for the Trendline and Display Equation and R² 10. Stop recording

13 RECORDING MACROS: EXAMPLE Go to Developer > Visual Basic to review the code in the Editor Sub Macro1() Selection.AutoFilter 'Activates Filtering ActiveSheet.Range("$A$1:$V$2565").AutoFilter _ Field:=4, _ 'Filters the 4 th column of Selection Criteria1:="NL West" 'For those in the NL West ActiveSheet.Range("$A$1:$V$2565").AutoFilter _ Field:=11, _ Criteria1:=Array( "1st of 4",, "1st of 7"), _ Operator:=xlFilterValues

14 RECORDING MACROS: EXAMPLE Range("B:B,I:I").Select ActiveSheet.Shapes.AddChart2(240, xlxyscatter).select ActiveChart.FullSeriesCollection(1).Trendlines.Add Type:=xlLinear,, DisplayEquation:=0, DisplayRSquared:=0, Name:="Linear (W.L.)" ActiveChart.FullSeriesCollection(1).Trendlines.Add ActiveChart.FullSeriesCollection(1).Trendlines(2).Select Selection.DisplayEquation = True 'Displays equation y=mx+b Selection.DisplayRSquared = True 'Displays R-squared value Application.CommandBars("Format Object").Visible = False 'Closes sidebar End Sub

15 HELLO, WORLD Let s try a few different ways to display Hello World Create a new module in the Project Window Edit the name of the module in the Properties Window (F4) Write the following code: Option Explicit 'You must explicitly Dim new variables As a data type Sub HelloWorld() 'Sets the content of Cell C5 to Hello World ActiveSheet.Range("C5").Value = "Hello World" End Sub In Excel, go to Developer > Code > Macros and click HelloWorld to run

16 HELLO WORLD: MESSAGE BOXES Create another module in the Project Window Write the following code: Option Explicit Sub HelloWorldPopUp() MsgBox "Hello World 'Generates a pop-up box End Sub In Excel, run this HelloWorldPopUp macro

17 HELLO WORLD: ONLOAD Create another module in the Project Window Write the following code: Private Sub Worksheet_Activate() MsgBox ("Thank you for coming to the workshop today!") End Sub Private Sub Worksheet_Deactivate() MsgBox ("Bye, I will miss you") End Sub In Excel, click this sheet, and then click away to see the MsgBoxes

BUTTONS You can create a button to run a macro when you click on it Step 1. Draw a button. Go to Developer > Controls > Insert > Button (Form Control) Draw the button Step 2.

18 BUTTONS You can create a button to run a macro when you click on it Step 1. Draw a button. Go to Developer > Controls > Insert > Button (Form Control) Draw the button Step 2. Assign a macro. Right-click on the button > Assign Macro > New/Edit Type the following code: Option Explicit Sub HelloWorld() ActiveSheet.Range("C5").Value = "Hello World" End Sub

19 REACTIONS You can write a macro to react to a user s action Option Explicit Private Sub Worksheet_SelectionChange(ByVal Target As Range) If Selection.Count = 1 Then If Not Intersect(Target, Range("F8")) Is Nothing Then MsgBox "Hello there" ElseIf Not Intersect(Target, Range("F10")) Is Nothing Then MsgBox "Oopsie, wrong button" End If End If End Sub

20 ARRAYS An array holds a list of elements of the same data type There are multiple ways to declare a static array. Dim myarray(0 To 3) As Integer 'Create array with locations 0,1,2,3 Dim myarray(3) As Integer 'Defaults as 0 to 3 i.e. locations 0,1,2,3 Dim myarray(1 To 5) As Integer 'Locations 1,2,3,4,5 You can set the values of elements myarray(3) = 97 'Sets the value of the 4 th element of myarray to be 97

21 ARRAYS CONTD. You can use the Array function to set the values in an array of Variants Dim arr1 As Variant arr1 = Array("Orange", "Peach", "Pear") Dynamic Arrays do not need the size to be specified upon declaration Dim dynarr1() As Variant 'Declares a dynamic array ReDim dynarr(x+1) 'Sets the size of the array to x+1 ReDim Preserve dynarr(x+3) 'Extends the size of the array by 2 while preserving existing data

22 DEVELOPMENT TRIANGLE The development triangle is used to project ultimate losses The triangle below shows losses for six accident periods (2012,, 2017) The loss amount for each accident period is shown at various ages (months after the beginning of the accident period) A B C D E F G

23 DEVELOPMENT TRIANGLE The triangle below is As of 12/31/2017. At 12/31/2018, we need to add a row (Acc. Per. 2018) and a column (age 96) Let s write a macro called AddOneYear() A B C D E F G

24 EXAMPLE: ADDING A YEAR TO A DEVELOPMENT TRIANGLE Option Explicit Sub AddOneYear() Application Range("B1").Select 'Begin in Cell B1 (Age 12) Dim lastage As Integer 'Will store the rightmost age (Age 84) 'Loop rightward across ages until the rightmost (Age 84) is found While IsEmpty(ActiveCell) = False lastage = ActiveCell.Value 'Store value as lastage found 'Select one cell to the right ActiveCell.Offset(0, 1).Select Wend ActiveCell.Value = lastage + 12 'Adds Age 96 to the right

25 EXAMPLE: ADDING A YEAR TO A DEVELOPMENT TRIANGLE Range("A2").Select Dim lastyear As Integer While IsEmpty(ActiveCell) = False lastyear = ActiveCell.Value ActiveCell.Offset(1, 0).Select Wend ActiveCell.Value = lastyear + 1 Range("A1").Select 'Return to Cell A1 End Sub

26 QUESTIONS?

VBA Collections A Group of Similar Objects that Share Common Properties, Methods and

VBA Collections A Group of Similar Objects that Share Common Properties, Methods and VBA AND MACROS VBA is a major division of the stand-alone Visual Basic programming language. It is integrated into Microsoft Office applications. It is the macro language of Microsoft Office Suite. Previously