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javabigdecimal

Java BigDecimal : How to fortmat BigDecimal

I'm using BigDecimal for counting some big real number. Although I have try two method : BigDecimal.toString() or BigDecimal.stripTrailingZeros().toString(), it still not sasitfy my requirement.

For example if I use stripTrailingZeros: 4.3000 becomes 4.3 but 4.0 becomes 4.0 not 4. Both above methods cannot sastisty those conditions. So, my question is : how to done it in java ?

Thanks :)

Solution

  • You can use DecimalFormat as follows: 

    BigDecimal a = new BigDecimal("4.3000");
BigDecimal b = new BigDecimal("4.0");

DecimalFormat f = new DecimalFormat("#.#");
f.setDecimalSeparatorAlwaysShown(false)
f.setMaximumFractionDigits(340);

System.out.println(f.format(a));
System.out.println(f.format(b));

    which prints

    4.3
4

    As Bhashit pointed out, the default number of fractional digits is 3, but we can set it to the maximum of 340. I actually wasn't aware of this behaviour of DecimalFormat. This means that if you need more than 340 fractional digits, you'll probably have to manipulate the string given by toString() yourself.