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Shift operators

Faqeer Khudaka
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Joined: Jan 24, 2006
Posts: 32
Hi,


I found this question in one of the mock exams:



Correct answer is A & B. My answer was B&C cause when 128 >> 1 is computed, the rule is that whatever the most significant bit is, that has to be "filled" from the left. In this case when 128(10000000) is shifted right by 1 bit, another 1 will be added cause initially the most significant bit of 128 was 1. This will give us 11000000 which comes out to be 192.
Am i correct??

Thanks
Faqeer
Jan Valenta
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Joined: Nov 30, 2005
Posts: 32
Don't forget that there is automatic promotion of the operands to ints. Therefore you are shifting (00000000 00000000 00000000 10000000) and the initial zero stays zero.

Jan


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ven kaar
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Joined: Nov 01, 2005
Posts: 39
i think the correct answer is 64 for both



http://java.sun.com/docs/books/tutorial/java/nutsandbolts/bitwise.html

considering 128 as int datatype

128 value is 00000000 00000000 00000000 10000000
based on the referred link above

>> 00000000 00000000 00000000 01000000 (fills with highest (sign) bit on the left side )
>>> 00000000 00000000 00000000 01000000 (fills with 0 bits on the left side )


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Faqeer Khudaka
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Joined: Jan 24, 2006
Posts: 32
Thanks guys.
I didnt pay attention to the int promotion thing.
Bert Bates
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Joined: Oct 14, 2002
Posts: 8815
    
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remember this topic is on the 1.4 exam, but it's NOT on the 1.5 exam.


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