Page 476 - Computer science 868 Class 12
P. 476

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
                Ans. class Godown
                    { String item;
                      int qty;
                      double rate,amt;
                      Godown(String i,int q,double r)
                      { item=i;
                        qty=q;
                        rate=r;
                        amt=q*r;
                     }
                     void display()
                     { System.out.print("Name:"+item+" Quantity "+qty+" Rate "+rate+" Amount "+amt);
                        }
                    }

                    class Update extends Godown
                    { int pur_qty;
                      double pur_rate;
                      Update(String i,int q,double r,int pq,double pr)
                      { super(i,q,r);
                        pur_qty=pq;
                        pur_rate=pr;
                    }
                    void update()
                    { qty=qty+pur_qty;
                      rate=pur_rate;
                      amt=qty*rate;
                    }
                    void display()
                    { System.out.println("Before updaton");
                      super.display();
                      System.out.println("After updaton");
                      update();
                      System.out.println("Qty"+ qty+" rate "+rate+" amount "+amt);
                    }
                    public static void main(String i,int q,double r,int pq,double pr)
                    { Update ob=new Update(i,q,r,pq,pr);
                      ob.display();
                      }
                    }
                                                                                              #Interdisciplinary
              D.  Java programs:                                                              #Experiential Learning
                  1.  A class D2Point defines the co-ordinates of a point in a plane, while another class D3Point defines the coordinates of a point in a
                    space. The details of both the classes are given below.                                    [ISC 2004]
                     Class name                            :   D2Point
                     Data Members
                     double x, y                           :   To store the values of x and y coordinates
                     D2Point(double nx, double ny)         :   Constructor to assign nx to x and ny to y
                     double distance2D(D2Point b)          :     To return distance between point object b and the current point object in
                                                               the plane using formula:
                                                                          2
                                                                                  2
                                                                 PQ =  (x − x 1 ) +  (y − y 1 ) assuming (x , y ) and (x , y ) as the two points.
                                                                              2
                                                                     2
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                474474  Touchpad Computer Science-XII
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