Question

a) Create saving account Class. Use a static data member annualBonusRate to store the annual bonus rate for each of the savers (objects)

b) The class contains a private data member savingBalance indicating the amount the saver currently has on deposit.

c) Provide member function calculate MonthlyBonus that calculates the monthly bonus by multiplying the savingBalance by annualBonusRate divided by 12; this bonus should be addad to savingBalance.

d) Provide a static member function modifyBunusRate that has a parameter and use it to set the static annualBonusRate to a new value.

e) Write a driver program (containing main) to test class SavingsAccount, saver1 and saver2, with balances of $2000.00 and $3000.00, respectively.

Set annualBonusRate to 3 percent only once

Then calculate the monthly bonus and print the new balance object , saver 1.

Will the annualBonusRatbe same for all objects? Explain the Answer.

Answer 1

As "annualBonusRate" is declared as static variable, value of "annualBonusRate" will be same for all objects....

Java Program:

class SavingsAccount
{
   static double annualBonusRate;
   private double savingBalance;
  
   //Constructor
   public SavingsAccount(double bal)
   {
       savingBalance = bal;
   }
  
   //Method that calculates monthly bonus
   public double MonthlyBonus()
   {
       return (savingBalance * (annualBonusRate)/12.0);
   }
  
   //Method that modified bonus rate
   public static void modifyBunusRate(double rate)
   {
       //Updating annualBonusRate
       annualBonusRate = rate;
   }
}

class SavingsAccountDriver
{
   //Main method
   public static void main(String args[])
   {
       //Creating objects
       SavingsAccount saver1 = new SavingsAccount(2000);
       SavingsAccount saver2 = new SavingsAccount(3000);
      
       //Set annualBonusRate to 3 percent
       SavingsAccount.modifyBunusRate(0.03);
      
       //Calculating monthly bonus
       System.out.println("Saver 1 Monthly Bonus: $" + (saver1.MonthlyBonus()));
       System.out.println("Saver 2 Monthly Bonus: $" + (saver2.MonthlyBonus()));
   }
}

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Sample Run: