Partial preview of the text
Download C programming easy notes and more Lecture notes C programming in PDF only on Docsity!
Programming Terminology Introduction to Program Design This chapter describes the various activities carried in a Program development to provide quality software. In case of software development the programmer have to decide % what todo? » howto do? and >» when to do. Before writing the programs he must decide that what steps the computer should follow to solve the identified problem. This should be framed in a step-by-step procedure. This systematic procedure used to solve a particular problem is called an algorithm. When this procedure is presented in the form of a chart, is called a flowchart. Traditionally program design has been linked with flowcharting. However, flowcharts are probable more useful in documentation rather than design. A complex structure of the problem creates the complexity in designing of flowchart. Flowcharting techniques are useful in describing program structure and in explaining programs. Some other techniques used to design programs are as follows : Modular Approach (Modular Design) In the early days of computer era, there were no well defined procedures for managing the software development process. The use of computers was limited to scientific and engineering applications. The programs were written for well-defined problems. If the program did not work, the programmer will correct it. People started calling this approach of program development as code-and- When the use of computers for solving complex problems started, the problems begin to appear with this approach. In many cases, it was found that the programmer could not really understand what the user wanted the program to do? And correcting problems often turned into an expensive and time consuming job. The programmers did not document their programs and even some programmers developed their own cryptic style so that they can secure their continued employment as no one else can figure out what the program is doing. Because of these practices, these early programs were almost impossible to debug and maintain, especially if the original programmer had left the company. To handle these problems, the Program Development Life Cycle (PDLC) was introduced in the 1970s, and is still in widespread use. The PDLC provides an organized plan for breaking down the task of program development into manageable chunks, each of which must be successfully completed before moving on to the next phase. The main aim of modular approach is to divide a project into segments and smaller units in order to simplify the analysis, design and programming efforts. "A method in which long programs ate divided into smaller programs or modules that can be designed, coded and debugged separately with a minimum amount of interaction is known as modular design, modular approach or modular programming.” Program Design Tools ‘The various program design tools are described below : (a) Structure chart : A structure chart is also known as an organogram hierarchy chart that shows the top-down design ofa program. Each box in the chart indicates a task that the program must accomplish. The lop module is also known as the main module or control module. TL ansfers the contral lo ather modules. Main Module Sub Module Sub Module ‘Sub Module I I I [ 1 [ 1 [ 1 Sub sub Sub sub |} Sub sub Sub sub | | Sub sub ‘Sub sub Module Module || Module Module | | Module Module Fig. 1.1 Structure Chart Study Material on “C Programming” by Saurabh Gupta Page 1 
