Question

A super class Godown has been defined to store the details of the stock of a retail store. Define a subclass Update to store the details of the items purchased with the new rate and update the stock. Some of the members of both the classes are given below:

Class name	Godown
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/methods:
Godown(…)	parameterized constructor to assign value to the data members
void display( )	to display the stock details

 

Class name	Update
Data members/instance variables:
pur_qty	to store the purchase quantity
pur_rate	to store the unit price of the purchased item
Member functions/methods:
Update(…)	parameterized constructor to assign values to the data members of both the classes
void update( )	to update the 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 updating

Assume that the super class Godown has been defined. Using the concept of inheritance, specify the class Update giving details of the constructor, void update ( ) and void display( ).

The super class, main function and algorithm need NOT be written.

Answer 1

class Update extends Godown
{
int pur_qty;
double pur_rate;
public Update(int ai, int qt, double rt, double am, int pqt, double prt)
{
super(ai, qt, rt, am);
pur_qty=pqt;
pur_rate=prt;
}
public void update()
{
qty+= pqt;
if(pur_rate !=rate)
rate=pur_rate;
amt=qty*rate;
}
public void display()
{
System.out.println("Stock details before updation");
super.display();
update();
System.out.println("Stock details after updation");
super.display();
}
}