Question

A super class Stock has been defined to store the details of the stock of a retail store.Define a subclass Purchase to store the details of the items purchased with the new rate and updates the stock. Some of the members of the classes are given below:
Classname:Stock
Data members/instance variables:

item:to store the name of the item
qty:to store the quantity of an item in stock
rate:to store the unit price of an item
amt:to store the net value of the item in stock

Member functions:
Stock(…):parameterized constructor to assign values to the data members
void display():to display the stock details
Classname:Purchase
Data members/instance variables:
pqty: to store the purchased quantity
prate: to store the unit price of the purchased item
Member functions / methods:
Purchase(…):parameterized constructor to assign values to the data members of both classes
void update():to update stock by adding the previous quantity by the purchased quantity and replace the rate of the item if there is a difference in the purchase rate . Also update the current stock value as:
(quantity*unit price)
void display():to display the stock details before and after updation
Specify the class Stock,giving details of the constructor() and void display().Using concept of inheritance,specify the class Purchase,giving details of the constructor(),void update() and void display().
THE MAIN() FUNCTION AND ALGORITHM NEED NOT BE WRITTEN.

Share code with your friends

Code

				
					public class Stock
{	
    String item;
    double qty,rate,amt;
    Stock(String a,double b,double c)
    {	
        item=a;
        qty=b;
        rate=c;
        amt=qty*rate;
    }
    
    void display()
    { 
        System.out.println("Name of the item:"+item);
        System.out.println("Quantity:"+qty);
        System.out.println("Rate per unit: "+rate);
        System.out.println("Net value:"+amt);
    }
}


public class Purchase extends Stock
{
    int pqty;
    double prate;
    Purchase(String a,double b,double c,int d,double e)
    {
        super(a,b,c);   
        pqty=d;
        prate=e;
    }

    void update()
    {
        qty=qty+pqty;
        rate=prate;
        amt=qty*rate;
        
    }
    
    void display()
    {	
        super.display();
        update();
        super.display();
    }
}