Question

Show with the help of an example, how the following base classes can be derived in class bill to fulfill the given requirement: 

class Elect 
   {
      String n; 
      float units; 
      public void setvalue() 
   {
      n = "SOURABH" 
      units = 6879; 
   }
}

class Bill uses data members charge and a member function to calculate the bill at the rate of ₹ 3.25 per unit and displays the charge. Class Elect is inherited by class Bill by using private visibility. 

Answer 1

Class elect can be derived in class bill as shown below:

class bill extends elect {
    private double charge;
    public void calc() {
        charge = 3.25 * units;
        System.out.println("Charge = " + charge);
    }
}