1. Chapter 2- Visual Basic Schneider
Problem Solving
Chapter 2- Visual Basic Schneider

2. Program Development Cycle Programming Tools
Outline and Objective
Program Development Cycle
Programming Tools
Chapter 2- Visual Basic Schneider

3. Program Development Cycle:
A step-by-step process enables the programmers to plan their programs, that enables you to use your time efficiently and helps you design error-free programs which produce the desired output.
Structured Programming
Using top_down design
Using modules
Using the three basic control structure
Defining and Documenting the Problem
Desired output
Needed input
Processing requirements
Designing and Documenting a Solution
Think of an algorithm , or a method of solution, for the computer to use.
This method must be a complete procedure for solving the problem in a finite number of steps.
Chapter 2- Visual Basic Schneider

4. Program Development Cycle steps:
1. Analyze: Define the problem.
Be sure you understand what the program should do and what the output should be.
2. Design: Plan the solution to the problem.
Find a logical sequence of steps that solve the
problem (Algorithm).
3. Develop the Interface: Select the objects (text boxes , command buttons, etc.).

5. Program Development Cycle steps:
4. Code: Translate the algorithm into a programming language.
5. Debug and Test: Locate and remove any errors in the program.
Testing: is the process of finding errors in a program.
Debugging: is the process of correcting errors that are found.
Bug: the error in a program.
6. Complete the Documentation: Organize all the materials that describe the program.
Debugging and Testing:
Syntax error
Run-time error
Logic error
Chapter 2- Visual Basic Schneider

6. Programming Tools (Problem solving tools):
Flowchart
Pseudocode
Hierarchy Chart (Structure chart)
Chapter 2- Visual Basic Schneider

7. Chapter 2- Visual Basic Schneider
What is a flowchart?
Diagram that visually represents the steps that the program performs to arrive at a solution.
A popular logic tool used for showing an algorithm in graphical form.
A flowchart consists of special geometric symbols connected by arrows.
Name: Flowlinee: Used to connect symbols and indicate the flow of logic
Terminal: Used to represent the beginning or the end of task
Input/output: Used for input and output operations, such as reading and printing.
Processing: Used for arithmetic and data manipulation operations
Decision: Used for any logic or comparison operations. Unlike the two other symbols , which have one entry and one exit flowline, the decision symbol has one entry and two exit paths.
Chapter 2- Visual Basic Schneider

8. Chapter 2- Visual Basic Schneider
Continue flowchart
Programmer draws flowchart before coding.
Most common flowchart symbols are:
Flowline: indicates flow of logic. (arrow )
Terminal: represents beginning or end of task (oval )
Input/Output: represents input or output operations (parallelogram )
Processing: data manipulation operations (rectangle )
Decision: used for logic or comparison operation (diamond )
The decision symbol has one entry and two exit paths. The path chosen depends on whether the answer to a question is “yes” or “no.”
Chapter 2- Visual Basic Schneider

9. Chapter 2- Visual Basic Schneider
Start
Example of Flowchart:
Initialize counter
and sum to 0
Are there more data? No
Yes
Get next grade
This is a program to insert grades and calculate the average
Increment counter
Add grade to sum
Determine the average grade of a class
Average=sum/counter
Print the average
Chapter 2- Visual Basic Schneider
Finish

10. Purpose of Flowcharting:
An aid in developing the logic of a program.
Verification that all possible conditions have been considered in a program.
Provides means of communication with others about the program.
A guide in coding the program.
Documentation for the program.
Chapter 2- Visual Basic Schneider

11. Chapter 2- Visual Basic Schneider
Desk Checking
The process of testing the flowchart with different data as input, and checking the output.
The test data should include nonstandard data as well as typical data.
Chapter 2- Visual Basic Schneider

12. Chapter 2- Visual Basic Schneider
What is Pseudocode?
An algorithm design technique that uses a combination of English words and Visual Basic statements
Used to create a rough sketch of the steps required to complete a task
The programmer can describe the algorithm without being restricted by any programming rules.
The Psedocode can easily be translated into the VB language
It is compact and the plan looks like the code to be written..
Chapter 2- Visual Basic Schneider

13. Example of Pseudocode:
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
Compute Average = Sum / Counter
Display Average
Chapter 2- Visual Basic Schneider

14. What is a Hierarchy Chart ? (Structure Chart)
Shows the overall program structure.
Describes what each part, or module, of the program does.
Also, shows how each module relates to other modules in the program.
Chapter 2- Visual Basic Schneider

15. Example of Hierarchy Chart:
Class average
Program
Get
Grade
Compute Sum and Number of Grades
Calculate
Average
Display
Average
Chapter 2- Visual Basic Schneider