Chapter 5Chapter 5Flowcharts and

programming Techniques

Introduction

A flowchart is a diagram consisting of labeled geometrical symbols together with rows connecting one symbol to another

A program flowchart pictures the sequence of instructions for solving a particular problem ( usually by means of a computer program).

Introduction

BOUNS = 0.03 * SALARY

Introduction The sequence of instructions for solving a particular problem is called algorithm.

Express the algorithm through a flowchart Easier to draw the flowchart than to write the program directly. Easier to understand than program Easy for development. Flowcharts are independent of any particular programming language

VARIABLES ,DATA-NAMES, PROGRAMMINGSATATEMENTS

a variable means a data item whose value may change during the execution of the program. Examples:-

Salary Bouns AVERAGE

Assignment Statements Salary = 500 Bouns = 0,03*Salary AVERAGE = ( T1+T2+T3)/3

VARIABLES ,DATA-NAMES, PROGRAMMINGSATATEMENTS

HOURS = HOURS + 12

Counter = Counter + 1

Input/Output Statements

Read NUMBER, HOURS,RATE

Write NUMBER, GROSS , NET

FLOWCHART SYMBLOS

FLOWCHART SYMBLOS

Terminal symbol

Input/Output symbol

FLOWCHART SYMBLOS

process symbol

FLOWCHART SYMBLOS

Decision symbol.

FLOWCHART SYMBLOS

Example: A company plans to give a year-end 3% to each of its employees. However, if an employee has been working 10 or more years at the company , he is to get an additional $50.

FLOWCHART SYMBLOS

FLOWCHART SYMBLOS

Example: The HP company plans to give a year-end 3% bonus to each of its employees earning $10,000 or more per year , and a fixed $300 bonus for the other employees.

FLOWCHART SYMBLOS

LOOPS AND THEIR CONTROL BY A COUNTER

LOOPS AND THEIR CONTROL BY A COUNTER

CONTROL OF LOOPS BYHEADER OF TRALIER RECORDS

Control by a Header Record

CONTROL OF LOOPS BYHEADER OF TRALIER RECORDS

Control by a Trailer Record

ACCUMULATORS

ACCUMULATORS

Example : Suppose that a company wants to find the total salary paid to its employees of a company.

TWO SPECIAL ALGORITHMS:

1. The average of the salaries,

TWO SPECIAL ALGORITHMS:

The largest salary

DO LOOPS

DO LOOPS

Example: A company has 80 employees . Draw a flowchart to find the average salary and the number of employees earning above the average salary

ExampleExample