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Shift operator conversions
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amarkirt saroay
Ranch Hand
Joined: Mar 16, 2008
Posts: 167
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I feel lost when i have to convert a number into a byte representaion from an int.Like if int i=168 then how to convert it into -88 in 8 bits? Another issue is if a byte =<some number exceeding 127> how to know what will be its equivalent form in byte representaion, say eg. System.out.println((byte)128); and System.out.println((byte)-128); Is there any quick tip for such conversions please....
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SCJP-75%
SCWCD-82%
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ioanis siafu
Greenhorn
Joined: Feb 06, 2008
Posts: 6
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168 has the 10101000 representation in binary. I think that the first byte(1) means it is a negative number. Then the bits of the number left (0101000) will be inversed. 0101000 -> 1010111. 1010111 is 88 in binary. The same happens with 128. 128 is represented 10000000 in binary. Fallowing this rule from 10000000 (- minus because the first digit is one)and inversing the rest of the number we obtain 1111111(127 in decimal). I don't know if this rule remains for large numbers.
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ioanis siafu
Greenhorn
Joined: Feb 06, 2008
Posts: 6
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I was wrong in my explications. The modulus of the two numbers added is 256.
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Nikhil Raj
Greenhorn
Joined: Mar 20, 2008
Posts: 16
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168 is represented as 10101000 in binary.The most significant bit is the sign bit which means that 10101000 is actually a negative number and not 168.To get the negative number, first take the one's complement of 10101000, ie 01010111. now add 1 to this which gives 01011000 which is 88. So the number represented by 10101000 is actually -88.
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Nikhil Raj
Greenhorn
Joined: Mar 20, 2008
Posts: 16
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for larger numbers only their least significant 8 bits are taken.. the rest are discarded.
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Ben Souther
Sheriff
Joined: Dec 11, 2004
Posts: 13410
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"Nikhil Raj R S", Please check your private messages regarding an important administrative matter. -Ben
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subject: Shift operator conversions
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