BBS: Inland Empire Archive
Date: 09-21-92 (21:38) Number: 104
From: RICK PEDLEY Refer#: NONE
To: REUVEN LAX Recvd: NO
Subj: And Or Xor Conf: (2) Quik_Bas
On 09-20-92 Reuven Lax wrote to All...
RL> I recently posted a question asking how to use AND OR XOR
RL> to set and rest and look at bits since then Ive figured out
RL> how to do that can sombody tell me what other uses it may have?
Many uses -- you've only looked at the fundamental way in which
it works. Here's an example of something I've used. In most
programming books, they show you how to determine whether a
number is odd like this:
INPUT "Enter a whole number: ", N
IF N/2 <> N\2 THEN PRINT N "is odd."
So 5/2 = 2.5 and 5\2 = 2 --> 5 is odd.
8/2 = 4 and 8\2 = 4 --> 8 is not odd.
A more elegant and faster method is replace the second line with
IF N AND 1 THEN PRINT N "is odd."
If the rightmost bit in N is set, then N must be odd, and N AND 1
evaluates to TRUE.
XOR can be used as a simple encryption method.
INPUT "Type something here: ", A$
Key = 221
Code$ = ""
FOR x = 1 TO LEN(A$)
Code$ = Code$ + CHR$(ASC(MID$(A$,x,1)) XOR Key)
To get the original string back, XOR Code$ with =the same number=.
Key = 221
A$ = ""
FOR x = 1 TO LEN(Code$)
A$ = A$ + CHR$(ASC(MID$(Code$,x,1)) XOR Key)
... OFFLINE 1.40 * It's getting cold in here...someone turn
on some more DX2'2!
--- Maximus 2.01wb
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