Java: Use DecimalFormat to format doubles and integers but keep integers without a decimal separator

decimalformat, double, integer, java

Solution

You can just set the `minimumFractionDigits` to 0. Like this:

public class Test {

    public static void main(String[] args) {
        System.out.println(format(14.0184849945)); // prints '14.01'
        System.out.println(format(13)); // prints '13'
        System.out.println(format(3.5)); // prints '3.5'
        System.out.println(format(3.138136)); // prints '3.13'
    }

    public static String format(Number n) {
        NumberFormat format = DecimalFormat.getInstance();
        format.setRoundingMode(RoundingMode.FLOOR);
        format.setMinimumFractionDigits(0);
        format.setMaximumFractionDigits(2);
        return format.format(n);
    }

}

Problem

I'm trying to format some numbers in a Java program. The numbers will be both doubles and integers. When handling doubles, I want to keep only two decimal points but when handling integers I want the program to keep them unaffected. In other words: Doubles - Input ``` 14.0184849945 ``` Doubles - Output ``` 14.01 ``` Integers - Input ``` 13 ``` Integers - Output ``` 13 (not 13.00) ``` Is there a way to implement this in the same DecimalFormat instance? My code is the following, so far: ``` DecimalFormat df = new DecimalFormat("#,###,##0.00"); DecimalFormatSymbols otherSymbols = new DecimalFormatSymbols(Locale.ENGLISH); otherSymbols.setDecimalSeparator('.'); otherSymbols.setGroupingSeparator(','); df.setDecimalFormatSymbols(otherSymbols); ```

Original source