Steps in Program Development, Schemes and Mind Maps of Information Technology

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Programming

Steps in program

development

Chapter 2

Steps in Program Development

• The various steps involved are
  • Defining or Analyzing the problem
  • Design (Algorithm)
  • Coding
  • Documenting the program
  • Compiling and running the program
  • Testing and Debugging
  • Maintenance

Unit 1 - Programming / Lecture 1 - Introduction 2

Tasks in defining a problem

• Followings are the tasks in order to define a problem - Specifying the input requirements - Specifying the output requirements - Specifying the processing requirements

Specifying the input requirements

• The input specification is obtained by answering following questions
  • What specific values will be provided as input to the program?
  • What format will the values be?
  • For each input item, what is the valid range of values that it may assume?
  • What restrictions are placed on the use of these values?

Specifying the processing requirements

• The processing requirement is obtained by answering following questions - What is the method (technique) required in producing the desired output? - What are the validation checks that need to be applied to the input data? - What calculations are needed?

Activity 1: Find Factorial Number

• Input?
• Output?
• Process?

Activity 1: Find Factorial Number

• Input : Positive integer number
• Output : Factorial of that number
• Process : Solution technique which transforms input to output. Factorial of a number can be calculated by the formula n!=123…n

Activity 2: Sum of numbers from 1 to n

• Input : Positive integer number
• Output : Sum of numbers from 1 to n
• Process : 2 methods

 Method A: You can add them up. It might take a while, depending on what N is, but let’s practice with N = 7. 1+2+3+4+5+6+7 = 28.

 Method B: You can look into a general case to try to find a formula:

Main elements of use-case diagram

Activity: Draw use-case diagram

You are hired to develop FAI’s library system with following description

• Admin who could
  • Manage books, readers (staff, lecturers, and students), etc.
  • Manage borrow/return books
• Users (staff, lecturers, students) who could
  • View/search books
  • Reserve books
  • Borrow/return books

Please draw Use-case diagram for this scenario

Modular Design

• Once the problem is defined clearly, several design methodologies can be applied
• An important approach is Top-Down program design
• It is structured design technique
  • It breaks up the problem into a set of sub-problems called Modules
  • It creates a hierarchical structure of the modules

STEPS IN Program Development: Coding

• An algorithm expressed in programming languages is called Program
• Writing a program is called Coding
• The logic that has been developed in the algorithm is used to write program

Forms of documentation

• Documentation comes in two forms
  • External documentation, which includes things such as reference manuals, algorithm descriptions, flowcharts, and project workbooks
  • Internal documentation, which is part of the source code itself (essentially, the declarations, statements, and comments)

Compiling and Executing the Program

• Compilation is a process of translating a source program into machine understandable form
• The compiler is system software
  • It examines each instruction for its correctness
  • It does the translation
• During the execution
  • Program is loaded into the computer’s memory
  • The program instructions are executed