The 3 Levels of Programming Language by Q7FZLLB

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									                                      Chapter 2
   Problem Solving




Chapter 2- Visual Basic   Schneider           1
      Outline and Objective


Program Development Cycle
    Programming Tools



    Chapter 2- Visual Basic   Schneider   2
     Program Development Cycle:

1. Analyze: Define the problem
2. Design: Plan the solution to the problem
3. Develop the Interface: Select the objects




              Chapter 2- Visual Basic   Schneider   3
    Program Development Cycle:

4. Code: Translate the algorithm into a
  programming language.
5. Debug and Test: Locate and remove any
  errors in the program.
6. Complete the Documentation: Organize all
  the materials that describe the program.


             Chapter 2- Visual Basic   Schneider   4
                    Programming Tools:

• Flowchart
• Pseudocode
• Hierarchy Chart (Structure chart)




              Chapter 2- Visual Basic   Schneider   5
                     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.




              Chapter 2- Visual Basic   Schneider   6
                                Continue flowchart

• Programmer draws flowchart before coding.
• Most common flowchart symbols are:
  –   Flowline
  –   Terminal
  –   Input/Output
  –   Processing
  –   Decision

                     Chapter 2- Visual Basic   Schneider   7
          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   8
Example of Flowchart:
                 Start

           Initialize counter
             and sum to 0


         Are there more data?
                                   No

                         Yes
           Get next grade


         Increment counter


          Add grade to sum

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                                          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   10
                   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




              Chapter 2- Visual Basic   Schneider   11
                 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   12
       What is a Hierarchy 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.



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        Example of Hierarchy Chart:

                     Class average
                       Program




          Compute Sum
 Get                               Calculate         Display
         and Number of
Grade                               Average          Average
             Grades

               Chapter 2- Visual Basic   Schneider             14

								
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