The following code gives me 14 for j..... but i don't know how....
class Test
{
public static void main(String args[])
{
int j;
int i;
i = 0xFFFFFFFF1;
System.out.println("i is " + i);
j = ~i;
System.out.println("j is "+j);
}
}
please help me in solving it manually.......
This does not compile!
>i = 0xFFFFFFFF1;
I think you've put one 'F' to many.
i, in binary form, would be:
1111 1111 1111 1111 1111 1111 1111 0001
Now, negative numbers are represented in 2's complement form.
So when you use this value it woud be first changed to:
0000 0000 0000 0000 0000 0000 0000 1110 //1's compement
0000 0000 0000 0000 0000 0000 0000 1111 //add 1 to make 2's complement
This is 15, but since it was originally negative, it'll be printed as -15. That's the first part; i is -15.
Now, when you apply the '~', it simply flips all the bits. So,
1111 1111 1111 1111 1111 1111 1111 0001
would become
0000 0000 0000 0000 0000 0000 0000 1110 //the one's complement mentioned earlier
And that's why you get j is 14.
Hex 0xFFFFFFF1 == Bin 11111111111111111111111111110001
~i ==
~11111111111111111111111111110001 ==
11111111111111111111111111110001 ^ 11111111111111111111111111111111 ==
00000000000000000000000000001110 ==
14 (decimal)
Message was edited by:
prometheuzz
Christ I'm slow again...
