Want my code to print only 2 decimal places

Question

public class Exercise05_08 {
  public static void main(String[] args) {
    System.out.println("Celsius\t\tFahrenheit\t|\tFahrenheit\tCelsius");
    System.out.println("---------------------------------------------");

    double celsius = 40; double farenheit = 120;
    for (int i = 1; i <= 10; celsius--, farenheit -= 10, i++) {
      System.out.println(celsius + "\t\t" + celsiusToFahrenheit(celsius) + "\t|\t" +     farenheit + "\t\t" + fahrenheitToCelsius(farenheit));
    }
  }

  public static double celsiusToFahrenheit(double celsius) {
    return (9.0 / 5.0) * celsius + 32;
  }

  public static double fahrenheitToCelsius(double fahrenheit) {
    return (5.0 / 9) * (fahrenheit - 32);
  }
}

Some of the values print out with several decimal places and i want all of the values to print with just 2 decimal places.

score 3 · Answer 1 · answered Feb 03 '14 at 23:01

You can have 2 decimal places using DecimalFormat:

DecimalFormat myFormatter = new DecimalFormat("#.00");
String output = myFormatter.format(value);

You can find additional information about custom formats and patterns construction (and how to use them) here.

score 0 · Answer 2 · edited Feb 03 '14 at 23:44

0

You should use the format() method:

System.out.format("%.2f", celsius);

will format the value with 2 decimal places.

Since you are using println() you may want to include "\n" in the end of your format strings to insert a newline.

edited Feb 03 '14 at 23:44

user207421

305,947
44
307
483

answered Feb 03 '14 at 23:01

mscoon

88
6

score 0 · Answer 3 · answered Feb 03 '14 at 23:01

Make the following change to not print only 2 digits after dot:

NumberFormat formatter = new DecimalFormat("%.2f");
String s = formatter.format(celsiusToFahrenheit(celsius));

And print:

System.out.println(celsius + "\t\t" + s + "\t|\t" + farenheit + "\t\t" + fahrenheitToCelsius(farenheit));

score -1 · Answer 4 · answered Feb 03 '14 at 23:02

-1

Easy fix would be to multiply the outcome by 100, cast them to an int, then divide them by 100 again to a double.

It might not be the most elegant solution, but it would work..

EDIT: apparently there's a more elegant solution, so forget it.

answered Feb 03 '14 at 23:02

Lonefish

647
2
11
32

No it doesn't. See [here](http://stackoverflow.com/questions/153724/how-to-round-a-number-to-n-decimal-places-in-java/12684082#12684082) for proof. – user207421 Feb 03 '14 at 23:44

Want my code to print only 2 decimal places

4 Answers4