C Programming - Bitwise Operators - Discussion

Discussion Forum : Bitwise Operators - Find Output of Program (Q.No. 1)
1.
Assunming, integer is 2 byte, What will be the output of the program?
#include<stdio.h>

int main()
{
    printf("%x\n", -1>>1);
    return 0;
}
ffff
0fff
0000
fff0
Answer: Option
Explanation:
Negative numbers are treated with 2's complement method.

1's complement: Inverting the bits ( all 1s to 0s and all 0s to 1s)
2's complement: Adding 1 to the result of 1's complement.
Binary of 1(2byte)     :  0000 0000 0000 0001
Representing -1:
1s complement of 1(2byte)    : 1111 1111 1111 1110
Adding 1 to 1's comp. result : 1111 1111 1111 1111
Right shift 1bit(-1>>1): 1111 1111 1111 1111 (carry out 1)
Hexadecimal            : f   f    f    f
(Filled with 1s in the left side in the above step)

Note:

1. Fill with 1s in the left side for right shift for negative numbers.
2. Fill with 0s in the right side for left shift for negative numbers.
3. Fill with 0s in the left side for right shift for positive numbers.
4. Fill with 0s in the right side for left shift for positive numbers.

Discussion:
26 comments Page 3 of 3.

Muruli said:   1 decade ago
Can any body can explain me the use of %x?

Nagamastan said:   1 decade ago
Very nice and thanks for the explanation.

Jaya said:   8 years ago
I am not understanding this.

Nandini said:   1 decade ago
What does ffff mean?

Mahesh said:   9 years ago
Thank you @Ahmed.

Mohan said:   9 years ago
What is %x?


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