Java program to calculate the sum of series

Table of Contents

Problem Statement:

Write a Java program to calculate the sum of the following series:

S = 3 – 6 + 9 – 12 + 15 – 18 …. – 30

Flowchart:

Raptor flow chart for the Java program is shown below:

Java Program:

package series;

/*****************************************************
 * Java Program:
 * To calculate the series sum shown below
 * sum = 3 - 6 + 9 - 12 + .... - 30 
 ******************************************************/

public class SeriesSum {
 //////////////////////////////////////////////////
 //main method
 /////////////////////////////////////////////////
 public static void main(String[] args) {
 // variables declaration
 int sum = 0;
 boolean minusSwitch = false;
 int term=0;
 int endTerm=30;
 // for loop 
 for(int i=3; i<=endTerm; i=i+3) {
 if(minusSwitch)
 term=-i;
 else
 term=i;
 //accumulating the sum
 sum += term;
 //toggle the switch
 minusSwitch = !minusSwitch ;
 } // end loop
 System.out.print("Sum of Series S = " + sum);
 } // end main
} // end class