Outline

1
Outline

• Software and Programming
• Program Structure
• Tools for Designing Software
• Programming Languages
• Introduction to Visual Basic (VBA)

2
ENGR 112

• Programming Languages

3
Types of Programming

• Procedural
• Strict sequence of processing steps
• Distinct start/stop points in program

include ltstdio.hgt main()
printf("Content-type text/html\n\n")
printf("lthtmlgt") printf("Hello
World!") printf("lt/htmlgt")
4
Types of Programming

• Event-Driven
• Waits for an event to trigger program execution
• Modular programming
• No start/stop point in program

5
Types of Programming

• Event-Driven

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Event-Driven
Procedure 1
Private Sub cmbDates_Click() Me.txtSSNScanned.SetF
ocus Call scanSSN End Sub Private Sub
cmdEndProgram_Click() If endProgram Then
End Else endProgram False End If End
Sub Private Sub txtSSNScanned_GotFocus() If
Me.cmbDates.Text "" Then MsgBox ("You need
to enter a date!") Me.cmbDates.SetFocus
Exit Sub End If End Sub
Procedure 2
Procedure 3
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Programming Languages

• Assembly Language
• Fast and most efficient
• Very difficult to program in
• Basic
• Beginners All-purpose Symbolic Instruction Code
• Easy to use
• Lacks total control

8
Programming Languages

• Fortran
• FORmula TRANslator
• Great for mathematical programming
• Not good for other uses, e.g. graphics
• C and C
• Powerful tools
• Harder to use/learn than BASIC
• Can do anything

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Programming Languages

• Visual Basic
• Develop windows programs easily
• Powerful tool
• Not as much control as Visual C
• VBA (Visual Basic for Applications)
• Visual C and C
• Develop windows applications
• Not easy to learn

10
VBA Macro Programming

• VBA is a general purpose programming language
  that comes standard with Excel or Office.
• Using VBA with Excel, powerful engineering
  analysis tools can be developed quickly and with
  minimum cost.
• VBA can be used for many engineering tasks
• communicating with engineering databases
• analyzing engineering data
• automating worksheet construction
• engineering modeling and simulation
• creating charts and engineering wizards (i.e.
  dialog boxes)
• creating GUI's

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Advantages of VBA

• Programmer does not need to be an expert Windows
  programmer
• Programmer creates GUI and defines what happens
  when user interacts with it
• Events are generated
• Push a button, move mouse, etc.
• This is called event-driven programming

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Visual Basic Overview

• Objects
• Events
• Numbers
• Strings
• Variables
• Operators

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Elements of a Visual Basic

• Objects Events

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Object Properties

• The most important properties (at least for the
  purpose of this course) are
• Name (objects name important!!)
• Caption (text to be displayed by the object)
• Font (what the text looks like)
• Visible (how it links to other applications)

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Objects With Names
lblEngr112
picCOE
txtInputA, txtInputB
picResults
cmdAddButton
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Visual Basic Events

• Change initiated by user
• Load a Form
• Click on a button
• Mouse down/up, Mouse drag
• Key down, key press, etc.
• Causes an event procedure (subprogram) to execute

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Elements of Visual Basic

• Data
• Constants (data that does not change)
• Numbers (e.g., 1234.56)
• Strings (e.g., this is a string)
• Variables (names of data holders)
• Numbers
• Strings
• Operators
• Arithmetic (, -, , /, etc.)
• String ()

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Visual Basic Integers

• Sequence of digits with no
• Commas
• Decimal points
• Negative numbers preceded by -
• Positive numbers optionally preceded by

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Single Precision Real Numbers

• Standard Representation
• Integer (whole number) portion
• Decimal point
• Unsigned integer (fractional) portion

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Visual Basic Strings

• String
• Sequence of characters (a, b, c, ..., 0, 1, 2,
  ..., , !, ...) treated as a unit
• Enclosed in double quotes in VB statement
• this is a string
• John Smith
• 737-2357
• a b

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Visual Basic Variables

• Variable
• Symbolic name for data value
• Name of data holder
• Name of a location in random access memory
• Variable names rules
• Must begin with a letter
• May contain only letters, digits, and underscores
  (_)
• Up to 255 characters long

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Variable Names

• a, b, c, ..., x, y, z
• distance, speed, time, average
• rateOfIncrease, startingTime, hoursPerWeek
• rate_of_increase, starting_time, hours_per_week

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Declaring Variable Types

• Two options
• Implicit declaration
• Explicit declaration
• Explicit declaration
• Dim name As String
• Dim count As Integer
• Dim average As Single
• Dim nextItem As Variant
• Explicit declaration is always preferable!!

25
VB Arithmetic Operators

• Addition () a b
• Subtraction (-) a - b
• Multiplication () a b
• Division (/) a / b
• Exponentiation () a b

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Arithmetic Order of Evaluation

• 1. Exponentiation (R - L)
• 2. Multiplication division (L-R)
• 3. Addition subtraction (L-R)

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Examples of Evaluation (1)
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Converting Formulas to VB
(1.0 / (a b)) 2 / ((1.0 / c 1.0 / d)
(e / f - g / h))
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String Operator

• Concatenation ()

good bye goodbye