#81842 - 2003-09-09 05:59 PM
DecToBin() and BinToDec()
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Radimus
Moderator
Registered: 2000-01-06
Posts: 5187
Loc: Tampa, FL
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we already have the dectohex version... the binary versions would be handy.
especially for things like: IP comparisons and subnet matching
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#81843 - 2003-09-10 09:44 AM
Re: DecToBin() and BinToDec()
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Richard H.
Administrator
Registered: 2000-01-24
Posts: 4946
Loc: Leatherhead, Surrey, UK
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Why limit it to a particular base?
code:
$iNewValue=BaseConvert($iOldValue,CurrentBase,RequiredBase, Optional WordSize)
The Optional WordSize would be required to deal with negative numbers and overflows.
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#81846 - 2003-09-15 02:14 PM
Re: DecToBin() and BinToDec()
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Kdyer
KiX Supporter
Registered: 2001-01-03
Posts: 6241
Loc: Tigard, OR
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quote:
How well does it handle negative values?
Probably needs to have an ABS() thrown in there before conversion..
Kent
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#81847 - 2003-09-15 03:52 PM
Re: DecToBin() and BinToDec()
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Richard H.
Administrator
Registered: 2000-01-24
Posts: 4946
Loc: Leatherhead, Surrey, UK
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Heh, no, that actually ignores the issue
What I'm talking about is (for example) binary representation of a negative number. Normally twos-complement - I don't think ones-complement is much used.
For example the offset for time zones is sometimes negative, which is stored in the registry as a twos-complement value.
That's why in my recommendation there is an optional word size - you need to know how wide the target is to construct a twos-complement value.
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