How can a Binary number be used in a program?
If you are asking about using binary constants, here are some public domain binary constant macros Tom Torfs published on Usenet. I'm a little concerned because last time I posted this here, the preview was correct, but the forum rendering was not -- here goes:
================================================================ From: tomtorfs@village.uunet.be (Tom Torfs) Newsgroups: comp.lang.c,comp.arch.embedded Subject: Binary constant macros Date: 26 Feb 2004 07:36:35 -0800 Hello All, I've been missing the lack of support for binary numeric literals in C. To get around it I wrote the following handy macros, which allows you to simply write something like: whatever = B8(10101010); and will translate as: whatever = 85; (compile-time constant) Code below... hopefully it's useful to some of you as well. greetings, Tom /* Binary constant generator macro By Tom Torfs - donated to the public domain */ /* All macro's evaluate to compile-time constants */ /* *** helper macros *** / /* turn a numeric literal into a hex constant (avoids problems with leading zeroes) 8-bit constants max value 0x11111111, always fits in unsigned long */ #define HEX__(n) 0x##n##LU /* 8-bit conversion function */ #define B8__(x) ((x&0x0000000FLU)?1:0) \ +((x&0x000000F0LU)?2:0) \ +((x&0x00000F00LU)?4:0) \ +((x&0x0000F000LU)?8:0) \ +((x&0x000F0000LU)?16:0) \ +((x&0x00F00000LU)?32:0) \ +((x&0x0F000000LU)?64:0) \ +((x&0xF0000000LU)?128:0) /* *** user macros *** / /* for upto 8-bit binary constants */ #define B8(d) ((unsigned char)B8__(HEX__(d))) /* for upto 16-bit binary constants, MSB first */ #define B16(dmsb,dlsb) (((unsigned short)B8(dmsb)<<8) \ + B8(dlsb)) /* for upto 32-bit binary constants, MSB first */ #define B32(dmsb,db2,db3,dlsb) (((unsigned long)B8(dmsb)<<24) \ + ((unsigned long)B8(db2)<<16) \ + ((unsigned long)B8(db3)<<8) \ + B8(dlsb)) /* Sample usage: B8(01010101) = 85 B16(10101010,01010101) = 43605 B32(10000000,11111111,10101010,01010101) = 2164238933 */ greetings, Tom
If this is true...
whatever = B8(10101010); and will translate as: whatever = 85;
I'm not sure I want to use this code.
10101010 in Binary = 0xAA in Hexadecimal.
Jon
Looks like Mr. Torfs has a typo. Further down just above the second of his two(!) signatures in "Sample usage:", he's got the same "... = 85" but this time it's B8(01010101), which is correct.
he's got the same "... = 85" but this time it's B8(01010101), which is correct.
Hmmm. I always thought 01010101 was 0x55. :-)
"I always thought 01010101 was 0x55."
You're closer than I was. Taking 01010101 by itself, I came up with 266305.
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