Show decimal of a double only when needed

25,627

Solution 1

The DecimalFormat with the # parameter is the way to go:

public static void main(String[] args) {

        double d1 = 1.234567;
        double d2 = 2;
        NumberFormat nf = new DecimalFormat("##.###");
        System.out.println(nf.format(d1));
        System.out.println(nf.format(d2));
    }

Will result in

1.235
2

Solution 2

Don't use doubles. You can lose some precision. Here's a general purpose function.

public static double round(double unrounded, int precision, int roundingMode)
{
    BigDecimal bd = new BigDecimal(unrounded);
    BigDecimal rounded = bd.setScale(precision, roundingMode);
    return rounded.doubleValue();
}

You can call it with

round(yourNumber, 3, BigDecimal.ROUND_HALF_UP);

"precision" being the number of decimal points you desire.

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Bigflow
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Bigflow

Updated on July 15, 2020

Comments

  • Bigflow
    Bigflow almost 4 years

    I got this problem with double (decimals).
    When a double = 1.234567 Then I use String.format("%.3f", myString);
    So the result is 1.234

    But when my double is 10
    The result will be 10,000
    I want this to be 10

    Is their a way to say that he only needs to show the decimals when it is "usefull"?

    I saw some posts about this, but that was php or c#, couldn't find something for android/java about this (maybe I don't look good).

    Hope you guys can help me out with this.

    Edit, for now I use something like this: myString.replace(",000", "");
    But I think their is a more "friendly" code for this.