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javabigdecimal

BigDecimal divide with a large number of decimal places

My question is very simple

In BigDecimal I want to do this:

public static void main (String [] args) {
    System.out.println(new BigDecimal(1).divide(new BigDecimal(3));
}

I want the result to be this : 0.333333333333333333333333333333333....... and not 0.3334 or 0.33.

Solution

  • All BigDecimal operations allow to set precision (number of digits after decimal point) and rounding mode.

    System.out.println(
    new BigDecimal(1).divide(new BigDecimal(3), 10, RoundingMode.HALF_UP));

    will output 0.3333333333. You can create a MathContext object to encapsulate this information. This is helpful since you typically need to do several operations with the same precision and rounding settings.

    MathContext mc = new MathContext(10, RoundingMode.HALF_UP);
System.out.println(new BigDecimal(1).divide(new BigDecimal(3), mc));
System.out.println(new BigDecimal(1).divide(new BigDecimal(9), mc));