Question

The goal of Java program(s) implemented as part of this assignment is:
1. To use for, while, do-while loops to solve the given problem(s)
2. Write custom method(s)
Note:
Be sure to document your code thoroughly. In other words, you must comment
each pertinent line of code to briefly state what it is intending to do.

Requirement-1

In the Requirement-1 you will create a program named
‘ComputeCompoundInterest, that will compute compound interest using the
formula as follows:
amount = principal * ( 1 + rate )numYears
(a) Ask the user to enter the following 3 data elements:
(i) The ‘Principal’
(ii) The ‘Interest Rate’
(iii) The ‘Number of Years’
(b) You will write the following 3 custom methods, each using a different loop
type to compute and print compound interest using the above mentioned
formula:
(i) “computeWhile”
(ii) “computeDoWhile”
(iii) “computeFor”
March 2, 2019
page 3
(c) Each method will take 3 parameters, as mentioned in (a) above, with the
right type, and will not be returning anything. So be sure the method
signature is defined the right way. Hint: return value should be ‘void’
(d) Each of the 3 methods should be called/invoked from the main() method of
your class
(e) The output from each of the 3 methods should look like the following. The
number of rows of output will depend on the number of years entered by
the user input. Sample output should like the following:
Output from ‘while’ loop:
Year 1 Amount: $xxx
Year 2 Amount: $yyy
…..
…..
Output from ‘do-while’ loop:
Year 1 Amount: $xxx
Year 2 Amount: $yyy
…..
…..
Output from ‘for’ loop:
Year 1 Amount: $xxx
Year 2 Amount: $yyy
…..
…..
Note:
• Please add a blank line after the output from each method is completed

Answer 1

Java Code:

Output Snapshot:

Text Code:

import java.io.*;
import java.util.Scanner; // Importing Scanner class for user input

public class Main
{
/* Main */
   public static void main(String[] args) {
   /* Creating scanner class object to take input from user */
   Scanner userInput = new Scanner(System.in);
  
/* Prompting user to input Principal Amount */
System.out.print("\nEnter Principal Amount :$");
double principal = userInput.nextDouble(); // Storing Double value from user
/* Prompting user to input Interest Rate */
System.out.print("\nEnter Interest Rate (0.00 - 1.00) :");
double interestRate = userInput.nextDouble(); // Storing Double value from user
/* Prompting user to input Number of Years */
System.out.print("\nEnter Number of Years :");
int numOfYear = userInput.nextInt(); // Storing Integer value from user
/* Calling methods to calculate compound interest */
       computeWhile(principal, interestRate, numOfYear);
       computeDoWhile(principal, interestRate, numOfYear);
       computeFor(principal, interestRate, numOfYear);
   }
  
   /*
   * Method Name : computeWhile
   * Input Arguments : principal : principal amount to calculate compound interest
   interestRate : interest rate on the principal amount
   numOfYear : number of years to calculate compound interest
   * Output Argument : void
   * Description : To calculate compound interest using while loop and display Output
   on output screen
   */
   public static void computeWhile(double principal, double interestRate, int numOfYear){
   System.out.println("\nOutput from ‘while’ loop:");
   int i=1; // loop counter initialisation
   while(i<=numOfYear){ // when counter value is less than or equal to numOfYear
   /* Calculating amount using compound interest formula */
   double amount = principal*Math.pow((1+interestRate),i);
   /* Displaying the output for each year */
   System.out.println("\t Year " + i + " Amount: $" + amount);
   /* Incrementing loop counter */
   i++;
   }
   }
   /*
   * Method Name : computeDoWhile
   * Input Arguments : principal : principal amount to calculate compound interest
   interestRate : interest rate on the principal amount
   numOfYear : number of years to calculate compound interest
   * Output Argument : void
   * Description : To calculate compound interest using do-while loop and display Output
   on output screen
   */
   public static void computeDoWhile(double principal, double interestRate, int numOfYear){
   System.out.println("\nOutput from ‘do-while’ loop:");
   /* Calculating amount using compound interest formula */
   int i=1;
   do{
   /* Calculating amount using compound interest formula */
   double amount = principal*Math.pow((1+interestRate),i);
   /* Displaying the output for each year */
   System.out.println("\t Year " + i + " Amount: $" + amount);
   /* Incrementing loop counter */
   i++;
   }while(i<=numOfYear);

   }
   /*
   * Method Name : computeFor
   * Input Arguments : principal : principal amount to calculate compound interest
   interestRate : interest rate on the principal amount
   numOfYear : number of years to calculate compound interest
   * Output Argument : void
   * Description : To calculate compound interest using for loop and display Output
   on output screen
   */
   public static void computeFor(double principal, double interestRate, int numOfYear){
   System.out.println("\nOutput from ‘for’ loop:");   
   for(int i=1; i<=numOfYear; i++){
   /* Calculating amount using compound interest formula */
   double amount = principal*Math.pow((1+interestRate),i);
   /* Displaying the output for each year */
   System.out.println("\t Year " + i + " Amount: $" + amount);
   }
   }
  
}

Explanation:

• The formula used for calculating the compound interest amount is as following:
• 
• Please note that, the interest rate range is 0.00 (for 0 % interest rate) to 1.00 (for 100% interest rate). For 10% interest rate, input must be 0.10.
• Please refer code comments for the understanding purpose.