Mock exam dout on JavaRanch regarding shift operator

[nagaraj raja]

Q)

 Assume bit pattern of byte x is 1011 0001 

What will the sign of x be after x>>2?
Ans)negative How

Assume the bit value is byte x 0010 0001.What the result of x>>2? 

Ans)0000 10101 How?
Please explain there answers

[Radiya Sojitrawala]

For the first bit pattern 1011 0001
note that this is a negative number and we are doing a signed right shift. In a signed right shift, we replace the MSBs(most significant bits whch are the leftmost bits) by the sign bit

so 1011 0001 >> 2
step1:_ _ 10 1100 // shift to right by 2
step2:1110 1100 // fill MSBs with sign bit which is one here

1110 1100 is a negative no because of 1 in the MSB.

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For the bit pattern 0010 0001

I think the answer should be 0000 1000 and not 0000 10101

[Philip Heller]

Shifting isn't covered in the 5.0 exam. Check out objective 7.6, which lists all the operators you need to know about.

-- Phil