Question

Java

Code the following interfaces - An interface called Accountable with void withdraw(double) and double getBalance() methods, and an interface called AccountReceivable with a void deposit(double) method. Save these two interfaces in separate Java files.

Then code a class, BusinessAccount, that implements the two interfaces defined above. Define and code the necessary instance variables and constructors. Override toString() so it will return the amount of a business account. Apply the particular operations, such as withdraw and deposit, required in implementing the interfaces. User cannot withdraw more than current balance and cannot deposit negative money. Create at least two objects of BusinessAccount with hard-coded data of your choice in the driver code to test the class and all functions described above.

Use of meaningful names for variables, classes, and methods and meaningful comments.

Answer 1

Code for your program is provided below. Code is extensively explained in code comments. Output screenshot as well as screenshot of properly indented code in IDE is attached. If you need any further clarification please feel free to ask in comments. I would really appreciate if you would let me know if the explanation provided is to your satisfaction

##########################################################################

Accountable.java

//interface Accountable
public interface Accountable 
{
         public void withdraw(double amount);   //method declaration
         public double getBalance();   //method declaration
         
}

AccountReceivable.java

//interface declaration
public interface AccountReceivable 
{
        public void deposit(double amount);   //method declaration
}

BusinessAccount.java

//class implements both interfaces
public class BusinessAccount implements Accountable, AccountReceivable {

        //private data member to hold balance 
        private double balance;
        
        //default constructor
        public BusinessAccount() {
                
                balance=0;    //balance is initiaized to zero 
        }
        
        //paramaterized constructor
        public BusinessAccount(double balance) {
                
                this.balance=balance;   //initialize balance with given parameter
        }
        
        @Override    //method to deposit amount
        public void deposit(double amount) {
                
                if(amount>=0)   //if the amount is positive
                        balance+=amount;   //increment the balance
        }

        @Override      //method to withdraw amount
        public void withdraw(double amount) {
                
                //if amount to be withdrawn is smaller than balance then withdraw else dont do anything
                if(amount<=balance)   
                        balance-=amount;   //decrement the balance
        }

        @Override    //method to get balance
        public double getBalance() {
                
                return balance;   //return balance
        }
        
        //to string method override
        public String toString()
        {
                return "Amount: $"+getBalance();   //retrurn balance amount
        }

        public static void main(String[] args) {
                
                BusinessAccount b1=new BusinessAccount(1000);  //object creation
                BusinessAccount b2=new BusinessAccount(7000);   //second object created
                
                System.out.println("Account b1 Initial details: ");
                System.out.println(b1);  //display details of first object
                
                System.out.println("\n$750 Deposit in b1");
                b1.deposit(750);   //deposit money
                System.out.println("Account b1 details: ");
                System.out.println(b1);   //display details
                
                System.out.println("\nTrying to add -500 deposit in b1");
                b1.deposit(-500);   //try to deposit negative amount
                System.out.println("Account b1 details: ");
                System.out.println(b1);   //display details
                
                
                System.out.println("\nAccount b2 initial details: ");
                System.out.println(b2);   //initial balance of second object
                
                System.out.println("\n$300 withdraw from b2");
                b2.withdraw(300);   //withdraw money
                System.out.println("Account b1 details: ");
                System.out.println(b2);    //display details
                
                
                System.out.println("\nTrying to withdraw $50000 withdraw from b2");
                b2.withdraw(50000);   //try to withdraw money more than the balance
                System.out.println("Account b1 details: ");
                System.out.println(b2);   //display details
                
        }
}

###########################################################################

OUTPUT

Account b1 Initial details: Amount: $1000.0 $750 Deposit in b1 Account b1 details: Amount: $1750.0 Trying to add -500 deposit in b1 Account b1 details: Amount: $1750.0 Account b2 initial details: Amount: $7000.0 $300 withdraw from b2 Account b1 details: Amount: $6700.0 Trying to withdraw $50000 withdraw from b2 Account b1 details: Amount: $6700.0

#######################################################################

SCREENSHOT OF CODE IN IDE

Accountable.java

1 //interface Accountable 2 public interface Accountable 3 4 public void withdraw( double amount); //method declaration 5 public double getBalance(); //method declaration 6 7} 8

AccountReceivable.java

1 //interface declaration 2 public interface AccountReceivable 3 { 4 public void deposit(double amount); 5} 6 //method declaration||

BusinessAccount.java

1 //class implements both interfaces 2 public class BusinessAccount implements Accountable, AccountReceivable { 3 4 1/private data member to hold balance 5 private double balance; 6 7 //default constructor 8 public BusinessAccount() { 9 LO balance=0; //balance is initiaized to zero 11 } 12 13 //paramaterized constructor 140 public BusinessAccount (double balance) { 15 16 this.balance-balance; //initialize balance with given parameter 17 } 18 190 @Override //method to deposit amount 20 public void deposit(double amount) { 21 22 if(amount>=0) //if the amount is positive 23 balance+=amount; //increment the balance 24 } 25 260 @Override //method to withdraw amount 27 public void withdraw(double amount) { 28 29 //if amount to be withdrawn is smaller than balance then withdraw else dont do anything BO if(amount<=balance) 31 balance- amount; //decrement the balance 32 } 33 340 @Override //method to get balance 35 public double getBalance() { 36 37 return balance; //return balance B8 } 39 10 //to string method override 110 public String toString() 12 {

return "Amount: $"+getBalance(); //retrurn balance amount } public static void main(String[] args) { BusinessAccount b1=new BusinessAccount(1000); //object creation BusinessAccount b2=new BusinessAccount (7000); // second object created System.out.println("Account b1 Initial details: "); System.out.println(61); //display details of first object System.out.println("\n$750 Deposit in b1"); b1.deposit(750); //deposit money System.out.println("Account b1 details: "); System.out.println(b1); //display details 43 44 45 1460 147 48 149 50 51 152 53 154 155 156 157 58 159 60 61 62 63 64 65 66 67 68 69 70 71 172 73 174 75 176 77 178 79 80 } System.out.println("\nTrying to add -500 deposit in b1"); b1.deposit(-500); //try to deposit negative amount System.out.println("Account b1 details: "); System.out.println(61); //display details System.out.println("\nAccount b2 initial details: "); System.out.println(62); //initial balance of second object System.out.println("\n$300 withdraw from b2"); b2.withdraw(300); //withdraw money System.out.println("Account b1 details: "); System.out.println(b2); //display details System.out.println("\nTrying to withdraw $50000 withdraw from b2"); b2.withdraw(50000); //try to withdraw money more than the balance System.out.println("Account b1 details: "); System.out.println(62); //display details| }