Visual Basic for Applications (VBA)
for Excel
Prof. Yitzchak Rosenthal
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Start the Visual Basic Editor
• Microsoft office applications (e.g. Excel , powerpoint, word, access)
have a built-in visual basic editor
• Choose menu choice "Tools | Macro | Visual Basic Editor"
The Visual Basic Editor
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Separate Windows
The VB editor is
opened in a
separate window
from the Excel
spreadsheet.
If you close the
VB editor you can
continue using the
spreadsheet.
IF YOU CLOSE
THE
SPREADSHEET,
THE VB
EDITOR WILL
CLOSE
Spreadsheet Window VB Editor Window
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Separate Code Sections
• There are different code
sections.
• Double click on a sheet or
workbook to enter code
for that sheet or
workbook.
Step1: Double
click here.
Step2: Enter
code for
sheet1
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Insert | Module
• Choose the
“insert | module”
menu to create a
new module.
• Modules contain
generic code that
is used by any
sheet.
Recording Macros
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Tools | Macro | Record New Macro
• Choose the menu choice “Tools | Macro | Record New
Macro” to start the macro recorder.
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Enter a name
• Enter a name for the Macro and press OK
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Stop Recording Button
• When you start recording a macro, the “Stop Recording” Toolbar
displays.
• Press the “stop recording” button when you are finished
performing the steps for the macro.
“Stop Recording” Button
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Perform the Steps for the Macro in Excel
• Perform whatever actions you want in Excel.
• Example:
– Step 1: insert a new line at the top of the spreadsheet.
– Step 2: click on cell A1 to select it
• Then press “stop recording”.
• See next slide for the VBA code that is created by
the macro recorder.
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See code in VB Editor
Look at the “Modules” in the VB Editor to see the code for the recorded macro.
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Execute the Macro
• To execute the macro, choose the menu choice, “Tools |
Macro | Macros”
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Run the Macro
Then
choose
the
macro
and
click
“Run”.
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The Macro is Executed
See the new row
VBA
vs
VB.Net
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VBA vs VB.Net
• You can use manyVB.Net concepts and code in VBA
• Like VB.Net, VBA also provides the ability to create
textboxes, buttons, checkboxes, radio buttons, etc. for use
in Excel (we will not cover how to do that here).
HOWEVER
• VBA is based on an older version of Visual Basic.
• There are some differences between how to write VBA and
VB.Net code.
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MsgBox vs MessageBox.Show
• MsgBox vs MessageBox.show
– VBA:
MsgBox ("Hello There")
– VB.Net:
MessageBox.Show("Hello There")
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No HANDLES clause in VBA
• Event Handlers
– VBA
• No "Handles" clause.
• Name of sub determines which event is handled
• Example
Private Sub Button1_Click()
MsgBox ("hello there")
End Sub
– VB.Net
• Needs "Handles" clause
• Name of sub does NOT determine which event is handled
• Example
Private Sub Button1_Click( ByVal sender As System.Object, _
ByVal e As System.EventArgs) _
Handles Button1.Click
MessageBox.Show("Hello there")
End Sub
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DIM may not use initialization value
• VB.Net
– In VB.Net you can declare a variable with Dim and give it an initial value all
in one step.
Dim number as Integer = 1
• VBA
– In VBA you MAY NOT use an initialization value in a Dim statement.
– Therefore the code above would not be legal.
– Instead do the following:
Dim number as Integer
number = 1
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Call
• Calling a Sub
– VBA:
• Must use the "Call" keyword if sub is in a different module
• Don't use parentheses if the sub doesn't contain any
parameters
• Example: Call DoIt
– VB.Net:
• Just use the name of the Sub
• Example: DoIt( )
Writing Your Own Code
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Sub
• Place all code to be executed in a "subroutine"
• Will explain more soon ...
Sub doSomething ( )
MsgBox ("Hello There")
MsgBox ("How are you doing?")
End Sub
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How to run (i.e. execute) a sub
• To execute the
subroutine:
– first :
place cursor
anywhere in the
Sub
– second :
Choose menu
choice:
Run | Run Macro
Sub doSomething ( )
MsgBox ("Hello There")
MsgBox ("How are you doing?")
End Sub
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Other ways to execute a sub
• To execute the
subroutine:
Sub doSomething ( )
– first :
place cursor
anywhere in the
Sub
– second :
Press F5
OR
press the "Run
macro" button
MsgBox ("Hello There")
MsgBox ("How are you doing?")
End Sub
What happens when you run this
subroutine?
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Running the subroutine
•
•
•
•
•
•
Excel spreadsheet displays
First message box appears.
Press OK
Second Message box appears
Press OK
subroutine is finished
(returns to the code window)
Sub doSomething ( )
MsgBox ("Hello There")
MsgBox ("How are you doing?")
End Sub
When you press OK the
2nd message box will
appear (not shown)
Functions
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Functions
• You can define your own VBA functions for use in
the Excel spreadsheet.
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Sample Function
This function calculates the sum of the values from
lowNumber to highNumber
Function summation(lowNumber As Integer, highNumber As Integer) as Integer
Dim count As Integer
summation = 0
For count = lowNumber To highNumber
summation = summation + count
Next count
End Function
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Using the sample function in Excel
Formulas View
ValuesView
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Rules for Functions
• The function has a type specified AFTER the
parameter list
– Function summation(lowNumber As Integer,
highNumber As Integer) as Integer
• The name of the function is used as a variable
inside the function
• The entire function call “becomes the value” that
the name of the function had when the function
finished executing.
Quick Intro to VB for the Novice
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Syntax
• Syntax
– syntax means the "grammar" of (or the rules for writing)
a programming language or command
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Syntax of SUB
• First line :
– Must type "Sub"
(without the
quotes)
– make up a name
for the sub
– must type
parentheses
• Body :
– Use VBA
statements
• Last Line:
– must type "End
Sub" (without the
quotes)
These are required
make up a name for
the Sub
(more later ...)
VBA
statements
go here
Sub doSomething ( )
MsgBox ("Hello There")
MsgBox ("How are you doing?")
End Sub
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More than one sub
• You can have many Subroutines
• Each subroutine must have a unique name
• When you execute a subroutine only it runs, not the
other subroutines
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Example
• Each sub
has a
unique
name
• You can
run each
sub
separately
Sub doSomething ( )
MsgBox ("Hello There")
MsgBox ("How are you doing?")
End Sub
Sub doSomethingElse ( )
MsgBox ("I am having fun.")
MsgBox ("Are you having fun?")
End Sub
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Rules for subroutine names
• Rules for Subroutine names
– must start with a letter
– can include
• letters (e.g. A B C a b c etc.)
• digits (e.g. 0 1 2 etc.)
• underscores (i.e. _ )
– may not be a VBA "keyword"
• some keywords are "sub", "end", "dim" (we'll see more later)
– may NOT include any "special" characters (e.g. !@# etc)
• Examples on next slide ...
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Examples
• Legal subroutine names
–
–
–
–
mySubroutine
hello
born2ride
born_to_ride
• Illegal subroutine names
– 3cheers
• may not start with a number
– bagels&lox
• may not include characters other than letters or nubmers or underscore ( _ )
– name with spaces
• may not include spaces in the name
END OF PRESENTATION
The following slides are “in progress”
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MsgBox ("Your message goes here")
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MsgBox( )
• MsgBox ( ) is used to display a dialog box with a message
to the user.
• Syntax:
– You must include the word "MsgBox" (without the quotes)
followed by a set of parentheses
– Place the message in the parentheses
– For now (until I teach you otherwise) assume that the entire
message should be enclosed in quotes (later we'll learn more
about when you don't need the quotes ...)
– For now (until I teach you otherwise) assume that the entire
statement must be typed on one line (later we'll learn how to
break up a long line ...)
• Example on next slide ...
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Example
Put the message in quotes.
• Sub showAMessageBox( )
MsgBox ("This will be displayed in a message box")
End Sub
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Numbers
• If your message only
includes a number, you do
NOT have to put it in
quotes (we'll explain why
later)
• Example: The following is
perfectly fine:
Sub showANumber( )
MsgBox(123)
End Sub
No quotes
necessary around a
number.
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Expressions
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Only one "value"
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String Expression
• String expressions
"This is a constant string expression"
"This is another string expression"
• Numeric expressions
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3+4
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• msgbox(<string expression>)
Differences between VB.Net and VBA
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MsgBox vs MessageBox.Show
VB.Net:
MessageBox.Show(“my message”)
VBA:
msgbox(“my message”)
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No HANDLES clause in VBA
• There is no Handles clause in VBA.
• In VBA the NAME of the sub indicates which
events it handles
– Example:
button1_click is the name of the click handler for the
button named button1