Java: Wrong results for division?

When dividing two integers, Java uses **integer division**. In integer division, the result is also an integer. The result is *truncated* (the fractional part is thrown away) and not *rounded* to the closest integer.



class Division {
    public static void main( String args[] ) {
      int i = 37;
      int j = 10;
      int r = i / j;
      System.out.println(r);
    }
}

# To get actual floating point result
Cast the numerator (or denominator) to `double`:

class Division {
    public static void main( String args[] ) {
      int i = 37;
      int j = 10;
      double r = (double) i / j;
      System.out.println(r);
    }
}

# To get rounded result
Following the same approach as above, cast the resulting `double` into a `long` using `Math.round`:

class Division {
    public static void main( String args[] ) {
      int i = 37;
      int j = 10;
      long r = Math.round((double) i / j);
      System.out.println(r);
    }
}

Wrong results for division in Java

Integer division in Java truncates the result. To get a floating point result, cast to double. For a rounded result, use Math.round.