How to multiply a BigDecimal by an integer in Java
How do you multiply a BigDecimal by an integer in Java? I tried this but its not correct.
import java.math.BigDecimal;
import java.math.MathContext;
public class Payment {
int itemCost;
int totalCost = 0;
public BigDecimal calculateCost(int itemQuantity,BigDecimal itemPrice){
itemCost = itemPrice.multiply(itemQuantity);
totalCost = totalCost + itemCost;
return totalCost;
}
You have a lot of type-mismatches in your code such as trying to put an int
value where BigDecimal
is required. The corrected version of your code:
public class Payment
{
BigDecimal itemCost = BigDecimal.ZERO;
BigDecimal totalCost = BigDecimal.ZERO;
public BigDecimal calculateCost(int itemQuantity, BigDecimal itemPrice)
{
itemCost = itemPrice.multiply(BigDecimal.valueOf(itemQuantity));
totalCost = totalCost.add(itemCost);
return totalCost;
}
}
If I were you, I would set the scale of the BigDecimal so that I dont end up on lengthy numbers. The integer 2 in the BigDecimal initialization below sets the scale.
Since you have lots of mismatch of data type, I have changed it accordingly to adjust.
class Payment
{
BigDecimal itemCost=new BigDecimal(BigInteger.ZERO, 2);
BigDecimal totalCost=new BigDecimal(BigInteger.ZERO, 2);
public BigDecimal calculateCost(int itemQuantity,BigDecimal itemPrice)
{
BigDecimal itemCost = itemPrice.multiply(new BigDecimal(itemQuantity));
return totalCost.add(itemCost);
}
}
BigDecimals are Object , not primitives, so make sure you initialize itemCost
and totalCost
, otherwise it can give you nullpointer while you try to add on totalCost
or itemCost
First off, BigDecimal.multiply()
returns a BigDecimal
and you're trying to store that in an int
.
Second, it takes another BigDecimal
as the argument, not an int
.
If you just use the BigDecimal
for all variables involved in these calculations, it should work fine.