Method won't return value

[footyvino]

Hi All,

Yet another Java newbie here learning the basics. :D

I can't figure out why this method 'fahrenheitToCelsius' won't return a double value. Can someone please help me?

public class TempConversion508 {
   public static void main(String[] args) {
      
      double test = fahrenheitToCelsius(120.0);
      System.out.println(test);
   }
   
   public static double fahrenheitToCelsius(double fahrenheit) {

      return (120.0 - 32.0) * (5 / 9);
   }
}

Output is: 0.0

Thanks!

Ash

[DarrylBurke]

Yup. 5 / 9 is integer division, which is rounded down.

Either use at least one double value 5.0 / 9 or 5 / 9.0 or cast one of the ints to double

((double) 5) / 9

db

db

[j2me64]

Output is: 0.0

the result is ok. if you devide two integer like you do ( 5 / 9 ) the result is an integer resp. 0, so your term become 0. to get a right result a quick solution is changing 5 or 9 to double 5.0 or 9.0 so that your term is (120.0 - 32.0) * (5 / 9.0). the result will now be automatically converted to an double so that the result of your term will be a double. an other solution is a explicit cast to double, like db explaine above.

the automatic type promotion is a very important and basic concept in java. so i suggest to spend enough time to learn it.