Need to round off two points after decimal digit

Question

I'm working on an app and facing an issue. I've tried a number of solutions but nothing solved my problem. I need to round off two digits after decimal point.

For Example.

9.225 should be rounded off to 9.23

Thank you.

Answer 1

For Kotlin use "%.2f".format(number), for Java use String.format("%.2f", number)

Result:

Answer 2

You can use String.format("%.2f", d), this will rounded automatically. d is your value.

OR

You can use this

double d = 1.234567;
DecimalFormat df = new DecimalFormat("#.##");
Log.d(df.format(d));

You can get as a float value as well like below.

float value = Float.valueOf(df.format(d)); // Output will be 1.24

Answer 3

I would have gone with a probable over the top solution however this is what i came up with.

It uses regex to split the string value of the number passed and then rounds up/down depending on the leading digit after the decimal place. It will return a Double in the instance but you can change that if you like. It does throw IllegalArgumentException, but thats taste dependant.

/**
 * @param value the value that is being transformed
 * @param decimalPlace the decimal place you want to return to
 * @return transformed value to the decimal place
 * @throws IllegalArgumentException
 */
Double roundNumber(@NonNull Double value, @NonNull Integer decimalPlace) throws IllegalArgumentException {
    String valueString = value.toString();

    if(valueString.length()> decimalPlace+1){
        throw new IllegalArgumentException(String.format("The string value of %s is not long enough to have %dplaces", valueString, decimalPlace));
    }

    Pattern pattern = Pattern.compile("(\\d)('.')(\\d)");
    Matcher matcher = pattern.matcher(valueString);

    if (matcher.groupCount() != 4) { //0 = entire pattern, so 4 should be the total ?
        throw new IllegalArgumentException(String.format("The string value of %s does not contain three groups.", valueString));
    }

    String decimal = matcher.group(3);
    int place = decimal.charAt(decimalPlace);
    int afterDecimalPlace = decimal.charAt(decimalPlace + 1);
    String newDecimal = decimal.substring(0, decimalPlace - 1);
    newDecimal += afterDecimalPlace > 5 ? (place + 1) : place;

    return Double.parseDouble(matcher.group(1) + "." + newDecimal);
}