Development of computer program
- 3. Problem Definition Program Design Coding Debugging Testing Documentation Maintenance
- 4. Software Developmen t Life Cycle(SDLC) 01 Problem Definition 02 Program Design 03 Coding 04 Debugging 05 Testing 06 Documentation 07 Maintenance
- 5. In this , a programmer studies a problem. He decides best way to solve the problem. Studding a problem is necessary because it helps a programmer to decide the following things: The facts and figures that is necessary to developing the program. The way in which the program will be designed. The language in which program is most suitable. What is the desired output and in which form it is needed?
- 6. The next stage is the program design. The software developer makes use of tools like algorithms and flowcharts to develop the design of the program. Algorithm Flowchart
- 7. Algorithm: • Start • Read a,b • Sum a+b • Product a*b • Print sum ,product • Stop Flowchart Start Read a,b Print sum,product Sum =a+b End Product=a*b
- 8. Once the design process is complete, the actual computer program is written, i.e. the instructions are written in a computer language. Coding is generally a very small part of the entire program development process and also a less time consuming activity in reality. In this process all the syntax errors i.e. errors related to spelling, missing commas, undefined labels etc. are eliminated. For effective coding some of the guide lines which are applied are : Use of meaningful names and labels of variables, Simple and clear expressions, Modularity with emphasis on making modules generalized, Making use of comments and indenting the code properly, Avoiding jumps in the program to transfer control.
- 10. At this stage the errors in the programs are detected and corrected. This stage of program development is an important process. Debugging is also known as program validation. Some common errors which might occur in the programs include: Un initialization of variables. Reversing of order of operands. Confusion of numbers and characters. Inverting of conditions e.g jumping on zero instead of on not zero.
- 12. A program must be tested in the process of program development. These process verifies the accuracy of a program. Different values are given as input and output is checked. The program may not give required output if it contains any error. It ensures that program gives desired result & problem is solved correctly.
- 13. Documentation is a very essential step in the program development. Documentation help the users and the people who maintain the software. It guides the user how to use the program. Another purpose of it , is to allow the some other programmer to modify the code if it necessary.
- 14. Updating and correction of the program for changed conditions and field experience is accounted for in maintenance. Maintenance becomes essential in following situations: Change in specification, Change in equipment, Errors which are found during the actual execution of the program.