1. Introduction to Programming
ENGR 112
Introduction to Programming

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

3. Software Written in a programming language Every language has a syntax
Language rules dictate writing program code
Syntax must be perfect for the program to work
What kinds of language rules?
Spelling
Punctuation
Placement of words in an instruction

4. Properly Working Program
Specific sequence of instructions
Don’t leave anything out
Don’t add in things that are not needed

5. Importance of Structure
Making a cake
Stir
Add two eggs
Add a gallon of gasoline
Bake at 350 degrees for 45 minutes
Add three cups of flour
BUT Instructions are
Out of order
Missing
Belong to another procedure

6. Running a Program The program can ONLY be run or executed
once syntax errors are removed
if the program appears to be written in a logical order

7. Program Elements Input- data, facts
Process – organize, check for accuracy, or do some calculations
Output – send results to printer, monitor, or speaker
Storage – send results to file to be used for input later

8. Program Structure
Large programs are never written as one huge series of steps.
Programs are broken down into units called modules.
Modules are also referred to as:
subroutines
functions
procedures
methods

9. Why Modularize? Allows multiple people to work on a problem
Enables reuse
Makes it easier to identify structures
Makes it easier to debug

10. Tools for Program Design
ENGR 112
Tools for Program Design

11. Flowcharts Used to structure logical flow of program
Create BEFORE you start creating code
Can help prevent errors in logic
Can speed up coding process since flow of program has been developed

12. Flowchart Symbols Flow of logic Connector I/O Processing Decision
Start/End
Flow of logic
Connector

13. ENGR 112
Flowchart Examples

14. Flow Chart for Determining the best way home

15. Flow Chart for Running a Bath

16. Payroll Program
Flow Chart for Determining Payroll Amount without Modules

17. Payroll Program with Modules
Flow Chart for Determining Payroll Amount with Modules

18. Creating Flowcharts #1
Read records from a file containing the name and batting average of all players in the league.  Write out the name and average of every player with an average of .200 or greater.

19. Creating Flowcharts #2
Read a file containing the high temperature of each day in December.  Write out the average high temperature for the month.  You can assume the input file includes only the 31 temperatures for December.

20. Creating Flowcharts #3
Design a program to create a graduation list given an input file of graduates including name and GPA for each graduate.  Any graduate with a GPA that is greater or equal to 3.8 should have "Dean's List" written next to his/her name. All others should have “ Graduate”  written next to his/her name. Finally  print “End of Graduation List -2002”.

21. Hierarchy Charts
You can use a hierarchy chart to illustrate modules’ relationships
A hierarchy chart does not tell you what tasks are to be performed within a module; it does not tell you when or how a module executes

22. Hierarchy Charts
Used to break down “tasks” associated with a program into sub-tasks
Illustrates relationship between tasks/subtasks
Useful in guiding structure of events in Visual Basic

23. Hierarchy Chart Examples
ENGR 112
Hierarchy Chart Examples

24. Hierarchy Chart Example

25. Value-Averaging Program

26. Hierarchy Chart Exercises
Allow a user to enter 5 numbers in any order, return and ordered list of numbers.
Allow a user to enter a word of any length, and return a count of the number of vowels.
Allow a user to enter any number, tell the user if a number is a prime number and if the number is odd or even.
Allow a user to enter a shape type and dimensions, tell the user which of two shapes has the largest area.

27. Pseudocode Definition
An outline of a program, written in a form that can easily be converted into real programming statements.
Definition from

28. Writing Pseudocode
Before you start typing your program, sit down and think about what you want to do. You might just run through in your head the steps you think you need, or you might jot some things down. THIS is what your pseudocode is.

29. Writing Pseudocode
When you decide how you are going to tackle the program, your ideas go through several levels of refinement. Similarly, the pseudocode can be more or less detailed depending on exactly what you want to put down.

30. ENGR 112
Pseudocode Examples

31. General Pseudocode Example
Build a matrix
– Put 1’s on main diagonal,
– Put 0.5’s on off diagonals
– Put numbers in corners

32. Detail Pseudocode Example
Build a matrix
Do “loop from 1 to size”
A(i,i) = 1
A(i+1,i) = -0.5
A(i,i+1) = -0.5
end Do
A(1,1) = ...–

33. Guess the Number Program
Get random number
Do ! loop until number is guessed
Prompt for user's guess
Get user guess
Compare against actual number:
If guess is higher,
print "too high!"
ElseIf guess is lower,
print "too low!"
Else
print "you guessed it!" and exit the program
Endif
End Loop ! go back for another guess

34. Bubble Sort Pseudocode
While not at end of list
compare adjacent elements
if second is greater than first
switch them
Else
get next two elements
if elements were switched
repeat for entire list

35. Important Points
Pseudocode does use loops or If/Then/Else statements, where needed.
You should not use exact syntax in your pseudocode, because someone should be able to look at your pseudocode and write a program in ANY language.
Pseudocode should be specific enough to give an idea of what type of program-flow you are thinking of.
Pseudocode shouldn't need comments but sometimes it helps to tell what the loops are for.

36. Generate Pseudocode Given a classroom full of people:
find the average height
the number of people
the height of the tallest person
the height of the smallest person

37. What Processes do we have?
getting a height
determining how many people are in the class
calculating an average
determining the tallest height
determining the smallest height

38. Decisions to be Made? Is this the last person?
Is the current height we have measured greater than  the current tallest height?
Is the current height we have measured smaller than  the current smallest height?

39. What Variables are Needed?
Current_Height (the height we have just measured)
Tallest
Smallest
Number_Of_Persons
Average_Height

40. Number_Of_Persons = 0
Average_Height = 0 Sum_Of_Heights = 0 Tallest = 0 Smallest = 10 DOWHILE NOT Last_Person INPUT Current_Height   Number_Of_Persons = Number_Of_Persons + 1   Sum_Of_Heights = Sum_Of_Heights + Current_Height    IF Current_Height > Tallest  
THEN Tallest = Current_Height   IF Current_Height < Smallest 
THEN Smallest = Current_Height END DOWHILE
Average_Height = Sum_Of_Heights / Number_Of_Persons

41. Pseudocode Examples Example #1.
Read records from a file containing the name and batting average of all players in the league.  Write out the name and average of every player with an average of .200 or greater.
Example#2
Read a file containing the high temperature of each day in December.  Write out the average high temperature for the month.  You can assume the input file includes only the 31 temperatures for December.
Example #3
Design a program to create a graduation list given an input file of graduates including name and GPA for each graduate.  Any graduate with a GPA that is greater or equal to 3.8 should have "Dean's List" written next to his/her name. All others should have “ Graduate”  written next to his/her name. Finally  print “End of Graduation List -2002”.

42. Pseudocode Exercises
Determine the average age of patrons during an evening at Clodfelters
Determine the greatest amount of money spent by a single customer during a day at Dari Mart
Determine the average amount of money spent on text books at the OSU bookstore on the first day of the term