Chapter 2 Problem Solving Chapter 2 Visual Basic

Chapter 2 Problem Solving Chapter 2 - Visual Basic Schneider 1

Outline and Objective l. Program Development Cycle l. 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: l l l Flowchart Pseudocode Hierarchy Chart (Structure chart) Chapter 2 - Visual Basic Schneider 5

What is a flowchart? l l 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 l l Programmer draws flowchart before coding. Most common flowchart symbols are: • Flowline • Terminal • Input/Output • Processing • Decision Chapter 2 - Visual Basic Schneider 7

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 Average=sum/counter Print the average Chapter 2 - Visual Basic Schneider Finish 8

Purpose of Flowcharting: l l l 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 9

Desk Checking l l 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? l l 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: l 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? l l l 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 13

Example of Hierarchy Chart: Class average Program Get Grade Compute Sum and Number of Grades Calculate Average Chapter 2 - Visual Basic Schneider Display Average 14