As specified in javadoc, a BigDecimal is defined by an integer value and a scale.
The value of the number represented by the BigDecimal is therefore (unscaledValue × 10^(-scale)).
So BigDecimal("1761e+5") has scale -5 and BigDecimal(176100000) has scale 0.
The division of the two BigDecimal is done using the -5 and 0 scales respectively because the scales are not specified when dividing. The divide documentation explains why the results are different.
dividepublic BigDecimal divide(BigDecimal divisor)Returns a
BigDecimalwhose value is(this / divisor), and whose preferred scale is(this.scale() - divisor.scale()); if the exact quotient cannot be represented (because it has a non-terminating decimal expansion) anArithmeticExceptionis thrown.Parameters:
divisor- value by which this BigDecimal is to be divided.Returns:
this / divisorThrows:
ArithmeticException— if the exact quotient does not have a terminating decimal expansionSince:
1.5
If you specify a scale when dividing, e.g. dividendo.divide(BigDecimal.valueOf(1000), 0, RoundingMode.HALF_UP) you will get the same result.
As specified in javadoc, a BigDecimal is defined by an integer value and a scale.
The value of the number represented by the BigDecimal is therefore (unscaledValue × 10^(-scale)).
So BigDecimal("1761e+5") has scale -5 and BigDecimal(176100000) has scale 0.
The division of the two BigDecimal is done using the -5 and 0 scales respectively because the scales are not specified when dividing. The divide documentation explains why the results are different.
dividepublic BigDecimal divide(BigDecimal divisor)Returns a
BigDecimalwhose value is(this / divisor), and whose preferred scale is(this.scale() - divisor.scale()); if the exact quotient cannot be represented (because it has a non-terminating decimal expansion) anArithmeticExceptionis thrown.Parameters:
divisor- value by which this BigDecimal is to be divided.Returns:
this / divisorThrows:
ArithmeticException— if the exact quotient does not have a terminating decimal expansionSince:
1.5
If you specify a scale when dividing, e.g. dividendo.divide(BigDecimal.valueOf(1000), 0, RoundingMode.HALF_UP) you will get the same result.
The expressions new BigDecimal("176100000") and new BigDecimal("1761e+5") are not equal. BigDecimal keeps track of both value, and precision.
BigDecimal("176100000") has 9 digits of precision and is represented internally as the BigInteger("176100000"), multiplied by 1. BigDecimal("1761e+5") has 4 digits of precision and is represented internally as the BigInteger("1761"), multiplied by 100000.
When you a divide a BigDecimal by a value, the result respects the digits of precision, resulting in different outputs for seemingly equal values.
You haven't specified a scale for the result. Please try this
2019 Edit: Updated answer for JDK 13. Cause hopefully you've migrated off of JDK 1.5 by now.
import java.math.BigDecimal;
import java.math.RoundingMode;
public class Main {
public static void main(String[] args) {
BigDecimal a = new BigDecimal("1");
BigDecimal b = new BigDecimal("3");
BigDecimal c = a.divide(b, 2, RoundingMode.HALF_UP);
System.out.println(a + "/" + b + " = " + c);
}
}
Please read JDK 13 documentation.
Old answer for JDK 1.5 :
import java.math.*;
public class x
{
public static void main(String[] args)
{
BigDecimal a = new BigDecimal("1");
BigDecimal b = new BigDecimal("3");
BigDecimal c = a.divide(b,2, BigDecimal.ROUND_HALF_UP);
System.out.println(a+"/"+b+" = "+c);
}
}
this will give the result as 0.33. Please read the API
import java.math.*;
class Main{
public static void main(String[] args) {
// create 3 BigDecimal objects
BigDecimal bg1, bg2, bg3;
MathContext mc=new MathContext(10,RoundingMode.DOWN);
bg1 = new BigDecimal("2.4",mc);
bg2 = new BigDecimal("32301",mc);
bg3 = bg1.divide(bg2,mc); // divide bg1 with bg2
String str = "Division result is " +bg3;
// print bg3 value
System.out.println( str );
}
}
giving wrong answer
public static double divide(double d1, double d2) {
BigDecimal b1 = new BigDecimal(d1);
BigDecimal b2 = new BigDecimal(d2);
return b1.divide(b2, 2, RoundingMode.DOWN).doubleValue();
}
This example returns 105.0000
public class TestBigDecimal {
static BigDecimal decimal = new BigDecimal(1050).setScale(4, BigDecimal.ROUND_HALF_UP);
static BigDecimal ONE_HUNDRED = new BigDecimal(100);
static BigDecimal TEN = new BigDecimal(10);
public static void main(String[] args)
{
BigDecimal decimalResult = decimal.divide(ONE_HUNDRED).multiply(TEN) ;
System.out.println(decimalResult);
}
}
You should adjust the scale during the creation of decimal variable.