VBA Programming Part One

Our Dartmouth Legacy 10 INPUT "What is your name: "; U$ 20 PRINT "Hello "; U$ 25 REM 30 INPUT "How many stars do you want: "; N 35 S$ = "" 40 FOR I = 1 TO N 50 S$ = S$ + "*" 55 NEXT I 60 PRINT S$ 65 REM

Startup Excel and hit… Alt-F11

First things first: Getting Help

Getting More Help

Project Explorer Excel objects User Forms Code Modules

Properties Window Properties are an object's characteristics, e.g. a sheet's name.

Immediate Window

Using the Immediate Window

Try the Immediate Window  MsgBox("Hello!")  x =  debug.Print x  'this is a comment  x = WorksheetFunction.Sum(1,2)  debug.Print x

Insert a module

Add some code Sub HelloWorld() MyName = InputBox("What is your name?") MsgBox ("Hi " + MyName) End Sub  Type "HelloWorld" in the Immediate Window to run your program.  Go back to Excel and run it from the Tools|Macro menu

Subroutines vs. Functions  Both are procedures: A named sequence of statements executed as a unit. (MS)  Functions return a value  Subroutines don't

Procedures take arguments

Arguments are variables

But what are variables?  "A named storage location that can contain data that can be modified during program execution." (MS) 1. Has name 2. Contains data 3. Can be modified

Convert Celsius to Fahrenheit Function Fahrenheit(Celsius) Fahrenheit = (Celsius * 1.8) + 32 End Function

Use the Function

Back to the Immediate Window x = 1 debug.Print x 1 x = 2 debug.Print x 2 'Set the value of x to 1 'Now set it to 2

Making Decisions

Decisions: If…Then Function VeryHot(Celsius) If (Celsius > 30) Then VeryHot = True Else VeryHot = False End If End Function

Which number is bigger? Function MyMax(x, y) If ( … ) Then … Else … End If End Function  Remember: 'FunctionName = Result'

Which number is bigger? (Solution) Function MyMax(x, y) If ( x > y ) Then MyMax = x Else MyMax = y End If End Function

Loops: For…Next For Variable = BeginValue to EndValue do something with Variable Next Sub firstLoop() For x = 1 To 10 Debug.Print x Next End Sub

Example: Sum of 1…N Function SumToN(N) SumToN = 0 For x = 1 To N SumToN = SumToN + x Next End Function

TemperatureChart  Create a sub called TemperatureChart  Use For…Next to loop Celsius from 0 to 40  Use debug.print to output the result of converting Celsius to Fahrenheit using our function

TemperatureChart (Solution) Sub TemperatureChart() For Celsius = 0 To 40 Debug.Print Fahrenheit(Celsius) Next End Sub

What we have covered so far…  The VBA environment  Inserting a module  Running a macro  Writing a user-defined function  Using the new function in Excel  Variables  If…Then…Else  For…Next