Q.19 Write short notes on following :
(i) Structured programming (ii) Flow chart. (AKTU. 2008-09)
Related Questions -
Q. Discuss the different symbols used in flow chart. (AKTU. 2011 - 12)
Q. Defie flow chart. What is the significance of flow chart in program design? (AKTU. 2013-14)
Ans. (i) Structured Programming: - (AKTU. 2012 - 13)
Structured programming can be seen as a subset of sub-discipline of procedural programming, one of the major programming paradigms. It is most famous for removing or reducing the Reliance on GOTO statement.
Structured programming is a data flow based methodology. The approach begins with a program specification that identifies inputs and outputs and describes the functional aspects of the system. The system specifications, then are used as a basis for the graphic representation-data flow diagram. (DFD) of the data flows and processes. From the DFD the next step is the definition of the modules and their relationships to one another in a form called a structure chart, using a data dictionary and other structured tools.
Structured programming partitions a program into small, independent modules. They are arranged in a hierarchy that approximates a model of the program and is organized in a top down manner with the details shown at the bottom. Thus structured programming is an attempt to minimise complexity and make a problem manageable by subdividing it into smaller segments, which is called modularization or decomposition. In this way structured programming minimizes intutive reasoning and promotes maintainable, provable systems.
Flow Chart: -
A flow chart is common type of chart, that represents an algorithm or process, showing the steps as a boxes of various kinds, and their order by connecting there with arrows. Flow charts are used in analyzing, designing, documenting or managing a process or program various fields.
Flow charts are used designing and documenting complex processes. Like other types of diagrams, they help us visualize what is going on and there by help the viewer to understand a process, and perhaps also find flows, bottle necks and other less obvious features within it. There are many different types of flows charts, and each type has its own repertoire of boxes and national conventions.
The two most common types of boxes in flow chart are –
(a) A processing step, usually called activity and denoted as a rectangular box.
(b) A decision usually denoted as a diamond.
There are many different types of flow charts. Sterneckert (2003) divides four more general types of flow charts.
(a) Document flow charts showing a document flow through a system.
(b) Data flow charts showing data flows in a system.
(c) System flow charts showing control at a physical or resource level.
(d) Program flow chart showing the controls in a program within a system.
FLOWCHARTING: -
Introduction: -
The flowchart is a means of visually presenting the flow of data through an information processing system, the operations performed within a system and the sequence in which they are performed. The program flowchart can be linked to the blueprint of a building. As we know that a designer draws a blueprint of a building before starting construction on a building. Similarly a programmer prefers to draw a flowchart prior to writing a computer program. As in case of the drawing of a blueprint, the flowchart is drawn according to defined rules and using standard flowchart symbols prescribed by the American National Standard Institute Inc.
Meaning of a Flowchart: -
A flowchart is a diagrammatic representation that illustrates the sequence of operations to be performed to get the solution of a problem.
Flowcharts are generally drawn in the early stages of formulating computer solutions. Flowcharts facilitate communication between programmers and business people. These flowcharts play a vital role in the programming of a problem and are quite helpful in under standing the logic of complicated and lengthy problems. Once the flowchart is drawn, it becomes easy to write the program in any high level language, often we see that flowcharts are helpful in explaining the program to others.
Hence it is correct to say that a flowchart is must for the better documentation of a complex program.
Guidelines For Drawing a Flowchart: -
Flowchart are usually drawn using some standard symbols; however some special symbols can also be developed when required. Some standard symbols, which are frequently required for flowcharting many computer programs are as follows -
