Restricting the length of strings...

Question

I'm wondering if it is possible to restrict the length of a string produced by the String.valueOf(double) method. Here is an example:
public class DoubleTest
     public static void main(String[] args)
          double d = 20.0;
          double d2 = 2.4;
          double value = (d/d2);
          String doubleString = String.valueOf(value);
          System.out.println(value);
}This code will output "8.333333333333334" when run. Is there a way to restrict it to fewer decimal places, for example: "8.34"?
Thanks a lot,
Eric

Answer 1

If you use DecimalFormat, you can specify the number of digits after the decimal point by using a 'pattern' in the constructor to DecimalFormat.
Use '#' in the pattern for digits which will not show any leading zeros.
Use '0' in the pattern for digits which will show zeros - this is the one to use after the decimal point to show how many decimal places you want showing.
This format will round the numbers either up or down depending on which is nearer.
See example below for usage :
import java.text.*;
public class DoubleTest{
     public static void main(String[] args)     {
          double d = 400000.0;
          double d2 = 2.4;
          double value = (d/d2);
          DecimalFormat df1 = new DecimalFormat("#.000");
        System.out.println(df1.format(value));
}This returns 166666.667 (i.e. 3 places after the decimal, rounded up).
Regards,
Fintan