Mail Archives: djgpp/1998/03/18/23:48:03
From: | "matthew p. conte" <spam AT somebody DOT else>
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Newsgroups: | comp.os.msdos.djgpp
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Subject: | Re: Binary << ?
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Date: | Wed, 18 Mar 1998 16:37:03 -0500
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Organization: | little, if any
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Lines: | 23
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Message-ID: | <6epegv$pi0@dfw-ixnews3.ix.netcom.com>
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References: | <01bd5261$69dc6a00$4a3e64c2 AT default>
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Reply-To: | "matthew p. conte" <dont AT bother DOT com>
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NNTP-Posting-Host: | alb-ny6-58.ix.netcom.com
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To: | djgpp AT delorie DOT com
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DJ-Gateway: | from newsgroup comp.os.msdos.djgpp
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laine wrote:
>Can someone tell me how the binary << work?
All kinds of off topic, but...
<< and >> are the binary shift operators. They shift the bits in a variable
or a number representation...
If you had an unsigned char b = 4; the bits look like this:
0 0 0 0 0 1 0 0
and you did a shift to the left by 1:
b = b<<1; (or even better b<<=1)
the bits would now be:
0 0 0 0 1 0 0 0
making b = 8. So just imagine that bitshifts to the left are multiplying by
powers of 2, and those to the right are dividing by powers of 2. So:
b >>= 3; is dividing by 2^3 or 8.
Good luck,
Matt.
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