explain me (double)

[Pankaja Shinde]

What happens when the following code gets executed:

class TechnoSample
{
public static void main(String[] args)
{
double d1 = 1.0;
double d2 = 0.0;
byte b =1;
d1 = d1/d2;
b = (byte) d1;
System.out.print(b);
}
}

(1) It results in the throwing of an ArithmeticExcepiton
(2) It results in the throwing of a DivideByZeroException
(3) It displays the value 1.5
(4) It displays the value �1


Answer : -------------------------
4

Please explain me answer.

Pankaj Shinde

[marc weber]

I think this is a special case that will probably not be on the exam.

The question is how to narrow a double value of Infinity (which results from double division by zero) to type byte. The process is described under JLS 5.1.3 Narrowing Primitive Conversions.

Basically, the double value is first converted to type int. Infinity is a special case in which the int's maximum value is used. In binary, this is 0111 1111 1111 1111 1111 1111 1111 1111. Next, the int is converted to a byte by discarding all but the 8 rightmost bits. This leaves 1111 1111, which is -1.