Question

Can you debug the following code using the given test code?public class SavingAccount{ // interest rate for all accounts private static double annualInterestRate = 0; private final double savingsBalance; // balance for currrent account // constructor, creates a new account with the specified balance public void SavingAccount( double savingsBalance ) { savingsBalance = savingsBalance; } // end constructor // get monthly interest public void calculateMonthlyInterest() { savingsBalance += savingsBalance * ( annualInterestRate / 12.0 ); } // end method calculateMonthlyInterest // modify interest rate public static void modifyInterestRate( double newRate ) { annualInterestRate = ( newRate >= 0 && newRate <= 1.0 ) ? newRate : 0.04; } // end method modifyInterestRate // get string representation of SavingAccount public String toString() { return String.format( "$%.2f", savingsBalance ); } // end method toSavingAccountString} // end class SavingAccount Using this test codepublic class SavingAccountTest{ public static void main(String[] args) { SavingAccount s1 = new SavingAccount(400); SavingAccount s2 = new SavingAccount(1000); SavingAccount.modifyInterestRate(0.05); System.out.printf("SavingAccount 1 is: %s\nSavingAccount 2 is: %s\n", s1, s2); s1.calculateMonthlyInterest(); s2.calculateMonthlyInterest(); System.out.printf("\nSavingAccount 1 after the interest is: %s\nSavingAccount 2 after the interest is: %s\n", s1, s2); SavingAccount.modifyInterestRate(.025); s1.calculateMonthlyInterest(); s2.calculateMonthlyInterest(); System.out.printf("\nSavingAccount 1 after the new interest is: %s\nSavingAccount 2 after the new interest is: %s\n", s1, s2); }}

Answer 1

Answer:

Explanation:

The reason the code was not working was due to a couple of errors. First, the SavingAccount class needed to be public so that it can be accessed within the same file. Secondly, the savingsBalance variable was set to final and therefore could not be modified, the final keyword needed to be removed. Lastly, the constructor for the SavingAccount class was incorrect. Constructors do not use the keyword void and instance class variables need to be referenced using the this keyword.

class SavingAccount{

   // interest rate for all accounts

    private static double annualInterestRate = 0;

    private double savingsBalance;

   public SavingAccount(double savingsBalance) {

       this.savingsBalance = savingsBalance;

   }

   public void calculateMonthlyInterest() {

        savingsBalance += savingsBalance * ( annualInterestRate / 12.0 );

    }// end method calculateMonthlyInterest

   // modify interest rate

   public static void modifyInterestRate( double newRate ) {

        annualInterestRate = ( newRate >= 0 && newRate <= 1.0 ) ? newRate : 0.04;

    } // end method modifyInterestRate

   // get string representation of SavingAccount

   public String toString() { return String.format( "$%.2f", savingsBalance );

    } // end method toSavingAccountString

}// end class SavingAccount

// Using this test codepublic

//

class SavingAccountTest{

   public static void main(String[] args) {

       SavingAccount s1 = new SavingAccount(400);

       SavingAccount s2 = new SavingAccount(1000);

       SavingAccount.modifyInterestRate(0.05);

       System.out.printf("SavingAccount 1 is: %s\nSavingAccount 2 is: %s", s1, s2);

       s1.calculateMonthlyInterest(); s2.calculateMonthlyInterest();

       System.out.printf("\nSavingAccount 1 after the interest is: %s\nSavingAccount 2 after the interest is: %s", s1, s2);

       SavingAccount.modifyInterestRate(.025);

       s1.calculateMonthlyInterest();

       s2.calculateMonthlyInterest();

       System.out.printf("\nSavingAccount 1 after the new interest is: %s\nSavingAccount 2 after the new interest is: %s", s1, s2); }}