Question

consider the code:

public double calculatePrice()
    { 
      int discount = 0 ;
      double totalPrice=itemCount*itemPrice;
      double netPrice;
      for(int i=0;i<NOOFITEMS.length;i++)
      {
        /*  if(i==0)
          {
              if(itemCount<NOOFITEMS[i])
               { discount=0;
                 break;
               }
          }
          /*if(i==NOOFITEMS.length-1)
          {  
        if(itemCount>NOOFITEMS[i])
           {  discount=50;
             break;
           }
          }
          if(itemCount<NOOFITEMS[i]&&itemCount>NOOFITEMS[i+1])
          {
            discount=DISCOUNTPERCENTAGE[i];  
          }*/
          discount=10;
      }
     System.out.println("discount "
             +discount);  
     System.out.println("totalprice "
             +totalPrice); 
      netPrice=totalPrice-(totalPrice*(discount/100));
      return netPrice;
    }

output::

Bill  ID:   501
Item NAME: grocery
 NO of Item: 11
 Price of Item: 250.0
discount 10
totalprice 2750.0
net price          2750.0
TRAINEE ID:   502
TRAINEE NAME: fruits
 Price of Item: 300.0
Item NO: 15
discount 10
totalprice 4500.0
net price         4500.0

The value of "netprice" should be 4050 [4500-(4500*(10/100)] as per the given statement.But the value is outputed as 4500 always..
the discount/100 is not computed correctly.Always the decimal part is ignored.
Can’t figure out the error..!

Answer 1

The culprit is:

totalPrice*(discount/100)

discount is an int, so discount/100 is an integer division and decimals get truncated. For example, 10/100 is 0.

To fix the issue, you can force the use of doubles:

totalPrice*(discount/100d)