java - adding n number of zeros after decimal

Question

I need to give accuracy of a number entered by user till few digit. like if user enter some random value and gives that he wants accuracy till three digit then I need to round off the digit till three places after decimal. So i did something like this

 int index = value.indexOf('.'); 
            if (index >= 0)
            {
                String fractional = value.substring(index);

                if (fractional.length() > decimalPlaces)
                {
                    floatValue = roundOffDecimals(floatValue, decimalPlaces);
                }
            }
            retVal = new Float(floatValue);

but when user enters some value but do not enters any value as decimal I need to display it as dismal value with zeros as number of decimal places. like for 15 is his number and 3 is his accuracy then I need to display number as 15.000

I am not able to display zero after decimal when it always changes. Please help. I tried DeciamlFormat df = new DecimalFormat("",#.##); but takes static value. And my accuracy keeps changing.

Any help will be appreciated.

Answer 1

You can indeed use NumberFormat to do this

double amount = 15;
NumberFormat formatter = new DecimalFormat("#0.000");
System.out.println("The Decimal Value is:"+formatter.format(amount));