1. Chapter 1 - An Introduction to Computers and Problem Solving
1.2 Windows, Folders, and Files
1.3 Program Development Cycle
1.4 Programming Tools
Chapter 1 - VB 2008 by Schneider

2. 1.1 An Introduction to Computers
Miscellaneous Questions
Chapter 1 - VB 2008 by Schneider

3. Programs Students Will Create in This Text
Create and manage a list of friends' addresses and phone numbers
Calculate loan payments and amortization
Computations to support other course work
Chapter 1 - VB 2008 by Schneider

4. Communicating with the Computer
Machine language – low level, hard for humans to understand
Visual Basic – high level, understood by humans, consists of instructions such as Click, If, Do
Chapter 1 - VB 2008 by Schneider

5. Computers and Complicated Tasks
Tasks are broken down into instructions that can be expressed by a computer language
A program is a sequence of instructions
Programs can be only a few instructions or millions of lines of instructions
Chapter 1 - VB 2008 by Schneider

6. All Programs Have in Common:
Take data and manipulate it to produce a result
Input – Process – Output
Input – from files, the keyboard, or other input device
Output – to the monitor, printer, file, or other output device
Chapter 1 - VB 2008 by Schneider

7. Chapter 1 - VB 2008 by Schneider
Hardware and Software
Hardware – the physical components of a computer
Keyboard
Disk drive
Monitor
Software – The instructions that tell the computer what to do
Chapter 1 - VB 2008 by Schneider

8. Chapter 1 - VB 2008 by Schneider
Programmer and User
Programmer – the person who solves the problem and writes the instructions for the computer
User – any person who uses the program written by the programmer
Chapter 1 - VB 2008 by Schneider

9. Chapter 1 - VB 2008 by Schneider
Problem Solving
Developing the solution to a problem
Algorithm – a step by step series of instructions to solve a problem
Problems are solved by carefully reading them to determine what data are
given and what outputs are requested. Then a step-by-step procedure is devised to
process the given data and produce the requested output. This procedure is called an
algorithm. Finally, a computer program is written to carry out the algorithm.
Algorithms are discussed in Section 2.2.
Chapter 1 - VB 2008 by Schneider

10. Types of Problems in this Text
Business computations
Managing records
Managing lists
And more
Chapter 1 - VB 2008 by Schneider

11. Chapter 1 - VB 2008 by Schneider
Visual Basic 2008
BASIC originally developed at Dartmouth in the early 1960s
Visual Basic created by Microsoft in 1991
Visual Basic 2008 is similar to original Visual Basic, but more powerful
Chapter 1 - VB 2008 by Schneider

12. Chapter 1 - VB 2008 by Schneider
XP versus Vista
Windows XP Windows Vista
Chapter 1 - VB 2008 by Schneider

13. 1.2 Windows, Folders, and Files
Windows and Its Little Windows
Mouse Actions
Files and Folders
Chapter 1 - VB 2008 by Schneider

14. Windows and Its Little Windows
Difference between Windows and windows.
Title bar indicates if window is active.
Chapter 1 - VB 2008 by Schneider

15. Chapter 1 - VB 2008 by Schneider
Mouse Actions:
Hover
Drag and drop
Click
Right-click
Double-Click
Pointing means moving your mouse across your desk until the mouse pointer is over
the desired object on the screen.
Hovering means to linger the mouse at a particular place and wait for a message or
menu to appear.
Clicking (sometimes people say single-clicking) means pressing and releasing the
left mouse button once. Whenever a sentence begins “Click on ,” you need to
1. move the mouse pointer until it is at the object you are supposed to click on and
2. press and release the left mouse button.
An example of a sentence using this jargon might be “Click on the button marked Yes.”
You also will see sentences that begin “Click inside the ” This means to move the
mouse pointer until it is inside the boundaries of the object, and then click.
Double-clicking means clicking the left mouse button twice in quick succession
(that is, pressing it, releasing it, pressing it, and releasing it again quickly so that
Windows doesn’t think you single-clicked twice). Whenever a sentence begins
“Double-click on ”, you need to
1. move the mouse pointer until it is at the object you are supposed to double-click
on and
2. press and release the left mouse button twice in quick succession.
For example, you might be instructed to “Double-click on the little box at the far left
side of your screen.”
Note: An important Windows convention is that clicking selects an object so you
can give Windows or the document further directions about it, but double-clicking tells
Windows to perform a default operation. For example, double-clicking on a folder will
open that folder.
Dragging usually moves a Windows object. If you see a sentence that begins “Drag
the ”, you need to
Chapter 1 - VB 2008 by Schneider

16. Chapter 1 - VB 2008 by Schneider
Files and Folders
File: holds programs or data. Its name usually consists of letters, digits, and spaces.
Folder: contains files and other folders (called subfolders).
Think of a disk as a large folder that contains several smaller folders each with its own name.
The naming of folders follow th same rule as naming files
Each folder is identified by listing its name preceded by a backslash
A filespec typically includes the drive, path and the filename.
File is identified by a small
directory or folder is identified by a folder icon
executable file: is identified by a rectangle with a thin bar across top
Go over: How to create a folder
to rename a folder
to delete a folder or file
to Copy a folder or file
To move a folder or file
Chapter 1 - VB 2008 by Schneider

17. Key Terms in using Folders and Files
Term Example
Disk Hard disk, CD
File name PAYROLL
Extension TXT
Filename PAYROLL.TXT
Path TextFiles\PAYROLL.TXT
Filespec C:\TextFiles\PAYROLL.TXT
Think of a disk as a large folder that contains several smaller folders each with its own name.
The naming of folders follow th same rule as naming files
Each folder is identified by listing its name preceded by a backslash
A filespec typically includes the drive, path and the filename.
File is identified by a small
directory or folder is identified by a folder icon
executable file: is identified by a rectangle with a thin bar across top
Go over: How to create a folder
to rename a folder
to delete a folder or file
to Copy a folder or file
To move a folder or file
Chapter 1 - VB 2008 by Schneider

18. Chapter 1 - VB 2008 by Schneider
Windows Explorer
Used to view, organize and manage folders and files.
Manage: copy, move, delete
Chapter 1 - VB 2008 by Schneider

19. Invoking Windows Explorer
Right-click on Windows Start button
Click on Explore in context menu
Chapter 1 - VB 2008 by Schneider

20. Display File Extensions (XP)
Alt/Tools/Folder Options
Click the View tab.
Uncheck "Hide extensions for known file types“.
Click OK.
Chapter 1 - VB 2008 by Schneider

21. Display File Extensions (Vista)
Click on Windows Start button.
Type Folder Options into Search box.
Press Enter key.
Click on View tab in dialog box.
Uncheck ″Hide extensions for known file types″.
Click OK.
Chapter 1 - VB 2008 by Schneider

22. 1.3 Program Development Cycle
Performing a Task on the Computer
Program Planning
Chapter 1 - VB 2008 by Schneider

23. Chapter 1 - VB 2008 by Schneider
Terminology tip
A computer program may also be called:
Project
Application
Solution
Chapter 1 - VB 2008 by Schneider

24. Program Development Cycle
Software refers to a collection of instructions for the computer
The computer only knows how to do what the programmer tells it to do
Therefore, the programmer has to know how to solve problems
Chapter 1 - VB 2008 by Schneider

25. Performing a Task on the Computer
Determine Output
Identify Input
Determine process necessary to turn given Input into desired Output
Chapter 1 - VB 2008 by Schneider

26. Problem-solving: approach like algebra class
How fast is a car traveling if it goes 50 miles in 2 hours?
Output: a number giving the speed in miles per hour
Input: the distance and time the car has traveled
Process: speed = distance / time
Chapter 1 - VB 2008 by Schneider

27. Pictorial representation of the problem solving process
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28. Chapter 1 - VB 2008 by Schneider
Program Planning
A recipe is a good example of a plan
Ingredients and amounts are determined by what you want to bake
Ingredients are input
The way you combine them is the processing
What is baked is the output
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29. Chapter 1 - VB 2008 by Schneider
Program Planning Tips
Always have a plan before trying to write a program
The more complicated the problem, the more complex the plan must be
Planning and testing before coding saves time coding
Chapter 1 - VB 2008 by Schneider

30. Program development cycle
1. Analyze: Define the problem.
2. Design: Plan the solution to the problem.
3. Choose the interface: Select the objects (text boxes, buttons, etc.).
Chapter 1 - VB 2008 by Schneider

31. Program development cycle continued
4. Code: Translate the algorithm into a programming language.
5. Test and debug: Locate and remove any errors in the program.
6. Complete the documentation: Organize all the materials that describe the program.
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32. Chapter 1 - VB 2008 by Schneider
1.4 Programming Tools
Flowcharts
Pseudocode
Hierarchy Chart
Direction of Numbered NYC Streets Algorithm
Class Average Algorithm
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33. Chapter 1 - VB 2008 by Schneider
Programming Tools
Three tools are used to convert algorithms into computer programs:
Flowchart - Graphically depicts the logical steps to carry out a task and shows how the steps relate to each other.
Pseudocode - Uses English-like phrases with some Visual Basic terms to outline the program.
Hierarchy chart - Shows how the different parts of a program relate to each other.
Chapter 1 - VB 2008 by Schneider

34. Chapter 1 - VB 2008 by Schneider
Algorithm
A step by step series of instructions for solving a problem (a recipe is an example of an algorithm)
Chapter 1 - VB 2008 by Schneider

35. Problem solving example
How many stamps do you use when mailing a letter?
One rule of thumb is to use one stamp for every five sheets of paper or fraction thereof.
Chapter 1 - VB 2008 by Schneider

36. Chapter 1 - VB 2008 by Schneider
Algorithm
1. Request the number of sheets of paper; call it Sheets. (input)
2. Divide Sheets by 5. (processing)
3. Round the quotient up to the next highest whole number; call it Stamps. (processing)
4. Reply with the number Stamps. (output)
Chapter 1 - VB 2008 by Schneider

37. Chapter 1 - VB 2008 by Schneider
Flowcharts
Graphically depict the logical steps to carry out a task and show how the steps relate to each other.
Chapter 1 - VB 2008 by Schneider

38. Chapter 1 - VB 2008 by Schneider
Flowchart symbols
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39. Flowchart symbols continued
Chapter 1 - VB 2008 by Schneider

40. Chapter 1 - VB 2008 by Schneider
Flowchart example
Chapter 1 - VB 2008 by Schneider

41. Chapter 1 - VB 2008 by Schneider
Pseudocode
Uses English-like phrases with some Visual Basic terms to outline the task.
Chapter 1 - VB 2008 by Schneider

42. Chapter 1 - VB 2008 by Schneider
Pseudocode example
Determine the proper number of stamps for a
letter
Read Sheets (input)
Set the number of stamps to Sheets / 5 (processing)
Round the number of stamps up to the next
whole number (processing)
Display the number of stamps (output)
Chapter 1 - VB 2008 by Schneider

43. Chapter 1 - VB 2008 by Schneider
Hierarchy charts
Show how the different parts of a program relate to each other
Hierarchy charts may also be called
structure charts
HIPO (Hierarchy plus Input-Process-Output) charts
top-down charts
VTOC (Visual Table of Contents) charts
All are similar to a company’s organization chart.
Chapter 1 - VB 2008 by Schneider

44. Hierarchy charts example
Chapter 1 - VB 2008 by Schneider

45. Divide-and-conquer method
Used in problem solving – take a large problem and break it into smaller problems solving the small ones first
Breaks a problem down into modules
Chapter 1 - VB 2008 by Schneider

46. Chapter 1 - VB 2008 by Schneider
Statement structures
Sequence – follow instructions from one line to the next without skipping over any lines
Decision - if the answer to a question is “Yes” then one group of instructions is executed. If the answer is “No,” then another is executed
Looping – a series of instructions are executed over and over
Chapter 1 - VB 2008 by Schneider

47. Chapter 1 - VB 2008 by Schneider
Sequence flow chart
Chapter 1 - VB 2008 by Schneider

48. Chapter 1 - VB 2008 by Schneider
Decision flow chart
Chapter 1 - VB 2008 by Schneider

49. Chapter 1 - VB 2008 by Schneider
Looping flow chart
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50. Direction of Numbered NYC Streets Algorithm
Problem: Given a street number of a one-way street in New York City, decide the direction of the street, either eastbound or westbound
Discussion: in New York City even numbered streets are Eastbound, odd numbered streets are Westbound
Chapter 1 - VB 2008 by Schneider

51. Chapter 1 - VB 2008 by Schneider
Flowchart
Chapter 1 - VB 2008 by Schneider

52. Chapter 1 - VB 2008 by Schneider
Pseudocode
Program: Determine the direction of a numbered NYC street
Get street
If street is even Then
Display Eastbound
Else
Display Westbound
End If
Chapter 1 - VB 2008 by Schneider

53. Chapter 1 - VB 2008 by Schneider
Hierarchy Chart
Chapter 1 - VB 2008 by Schneider

54. Class Average Algorithm
Problem: Calculate and report the grade-point average for a class
Discussion: The average grade equals the sum of all grades divided by the number of students
Output: Average grade
Input: Student grades
Processing: Find the sum of the grades; count the number of students; calculate average
We need a loop to read and then add (accumulate) the grades for each student in the class. Inside the loop, we also need to total (count) the number of students in the class. See Figures 2.8 to 2.10.
grade = sum of grades / number of students.
Chapter 1 - VB 2008 by Schneider

55. Chapter 1 - VB 2008 by Schneider
Flowchart
Chapter 1 - VB 2008 by Schneider

56. Chapter 1 - VB 2008 by Schneider
Pseudocode
Program: Determine the average grade of a class
Initialize Counter and Sum to 0
Do While there are more data
Get the next Grade
Add the Grade to the Sum
Increment the Counter
Loop
Computer Average = Sum / Counter
Display Average
Chapter 1 - VB 2008 by Schneider

57. Chapter 1 - VB 2008 by Schneider
Hierarchy Chart
Chapter 1 - VB 2008 by Schneider

58. Chapter 1 - VB 2008 by Schneider
Comments
When tracing a flowchart, start at the start symbol and follow the flow lines to the end symbol
Testing an algorithm at the flowchart stage is known as desk checking
Flowcharts, pseudocode, and hierarchy charts are program planning tools that are not dependent on the programming language being used
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59. Chapter 1 - VB 2008 by Schneider
Comments continued
There are four primary logical programming constructs
sequence
decision
loop
unconditional branch
There are four primary logical programming constructs: sequence, decision, loop,
and unconditional branch. Unconditional branch, which appears in some lan-guages
as Goto statements, involves jumping from one place in a program to anoth-er.
Structured programming uses the first three constructs but forbids the fourth.
Chapter 1 - VB 2008 by Schneider

60. Chapter 1 - VB 2008 by Schneider
Unconditional branch
Appear in some languages as Goto statements
Involves jumping from one place in a program to another
Structured programming uses the sequence, decision, and loop constructs but forbids the unconditional branch
Chapter 1 - VB 2008 by Schneider

61. Tips and tricks of flowcharts
Flowcharts are time-consuming to write and difficult to update
For this reason, professional programmers are more likely to favor pseudocode and hierarchy charts
Because flowcharts so clearly illustrate the logical flow of programming techniques, they are a valuable tool in the education of programmers
Chapter 1 - VB 2008 by Schneider

62. Tips and tricks of pseudocode
There are many styles of pseudocode
Some programmers use an outline form
Some use a form that looks almost like a programming language
The pseudocode in the case studies of this text focus on the primary tasks to be performed by the program and leaves many of the routine details to be completed during the coding process
Chapter 1 - VB 2008 by Schneider

63. Tips and tricks of hierarchy charts
Many people draw rectangles around each item in a hierarchy chart
In the text, rectangles are omitted to encourage the use of hierarchy charts by making them easier to draw
Chapter 1 - VB 2008 by Schneider