1. Data and Flowcharts Session
Deborah Becker

2. Agenda The programming process Data hierarchy
Assigning values to variable
The three basic structures
Is my program structured
Exercises

3. Programming Process Understand the problem Plan the logic
Code the problem
Test the program
Put the program into production

4. Understand the problem!
Programs satisfy users needs
HR wants a list of employees who have been with the company over five years
Understand what the users wants
This is the probably the most important step in planning your program.
Does HR want a list of full time employees or should the list include part-time as well? Should the list include contract employees?
What starting date should be used to begin the query? Do they want only those who worked for the company continuously for five years or should you include those employees that may have taken family leave but returned? The programmer must not make assumptions about what the user wants. What do they want the report to look like? What data should the report include; first and last name, phone, ssn. Is all this data contained in one file or will several files need to be opened? You will need to ask the user for things link print layout and file specification data.

5. Plan the logic Develop your algorithm
This is not the time to worry about the syntax of the language
You can test the logic by creating several records to put through your logic structure manually
The programming plans each task or step of the program. You also need to determine the execution order of each step.
We will use our pseudocode and flowchart tools to help us plan the order of the instructions.

6. Code the Program
This is where the programmer needs to worry about the syntax.
If the planning stage was developed successfully the coding step will require less time.

7. Test and Retest
Programs that are free of syntax errors are not necessarily free of logic errors.
This step will require a set of test data

8. Production
After the testing produces clean output the program will be ready to place into production
Allow the user to use the program
Any good user can find any unresolved bug in even the most error free code?
Fixing bug problems and modifying the code is called maintenance programming.
About half of your will go on to be maintenance programmers and you will become experienced documentation interpreters.

9. Six Basic Computer Operations
Receives Information
Outputs Information
Performs Arithmetic
Assigns value to variables
Compares variables
Repeat groups of instructions

10. Data Hierarchy Database File—(User defined type/Class)
Record—(Class Instance/object)
Field—(Attribute)
The individual pieces of data that describe each instance of the file or class.
Character
Employee Class or file
attributes
strFirstName
strLastName
strAddress
strPhone
strSSN
sngSalary

11. Problem!
Write a program to read the instances of an employee class. Print employee class list report of those with 4 or more years of employment.
Attributes to collect
Name (First and Last)
Address (Street, City, State, Zip)
Social Security Number
Phone Number
Years of employment

12. Step 1 Do you Understand the Problem? Yes No Create your task list
Define all the steps needed to solve the problem
Don’t worry about the order of the steps until you feel that your list is complete. No
Ask the user questions until your know the answer to all your questions.
Do you have a copy of the report layout?
Task list
1. Start
2. Open employee file
3. Process records while not EOF
4. Read first record
5. If years of employment >= 4 then add to report
6. If years of employment < 4 read next record
7. If end of file = true then Print report
9. Close data file
10. End

13. Step 2 Put the task in order of operations Construct your flowchart
Fill in your task list
Fill in your flowchart symbols for each task
Construct your flowchart

14. Step Three Draw the User Interface
Draw the objects from the tool box on the user interface that you need to solve the problem
Write the object name beside each object
Indicate Attribute name if a data file is going to be used
REMEMBER CLASS IS ANOTHER NAME FOR DATA FILE
ATTRIBUTE IS ANOTHER NAME FOR FIELD
Generate Pseudocode, Flowchart

15. Steps Three cont. Code the problem Use Pseudocode, Flowchart
Create project in coding editor
When the runtime errors have been eliminated you are ready for step four.

16. Step Four Create Sample records Create two or three records.
Desk check your flow chart to make sure that your data and logic solve the algorithm.
Add any needed structure changes.
Data records will usually be supplied with the problem definition sheet.

17. Structures There are three basic structures from which all logic flows
Sequences
Selection (decisions)
Loops (repetition)
Diagram a sequence on the boars
Diagram a selection on the board
Diagram a loop structure on the board

18. Structures
Selection
Loop
Sequence IF
While

19. Solving Algorithms
All problems can be solved using only these three structures
They can be combined in infinite ways
Each must have one entrance and one exit
This make the program structured
Attaching the structures end to end is called stacking

20. Other steps
Use your Flowchart Form and write your pseudocode to the right of your flowchart.
Remember there are no set rules—this is a tool to help you when you begin to code your solution.
Use structured statement form and indentations to make the logic more apparent.

21. Example Pseudocode Do step A Do Step B If Condition C is true then
Do Step D
Else
Do Step E
Endif
While condition F is true
Do Step G
Step a
Step b
If C
Yes No
You can have a sequence inside a selection structure or inside a loop. Programs can become very complicated but remember each structure must have one way in and one way out.
Step e
Step d
Yes
While F
Step g No

22. Things that will help? Yeah! Your ready to turn on the computer.
Completed task list (order your task)
Draw your flowchart
Desk check your data
Does the data flow into and out of your structure correctly?
Draw your User Interface and Name your objects
Write your pseudocode
Yeah! Your ready to turn on the computer.