Whats a low-order byte or an high-order byte?

[SameerThigale]

In the C Reference Manual, Denis Ritchie says, "...a character constant of length 1 has the code for the given characters in the low byte and 0 in the high order byte..."
What does this mean?

[helios]

The text must be outdated and refer to some prototype of C. In modern C, "character" and "byte" are synonyms, so the sentence is meaningless.

[SameerThigale]

But,in practical, is there any concept of low order byte or high order byte?

[helios]

Not when talking about characters. When talking about multibyte values, the low order byte is the least significant byte. As an analogy with the decimal system, in the number "1024", "4" is the least significant digit.

[andywestken]

The char literal size is a C versus C++ issue

From http://en.wikipedia.org/wiki/Compatibility_of_C_and_C%2B%2B

For example, character literals such as 'a' are of type int in C and of type char in C++, which means that sizeof 'a' will generally give different results in the two languages: in C++ it will be 1 in C it will be sizeof(int) which on architectures with 8 bit wide char will be at least 2.

[helios]

Huh. Kind of weird, but not much of a problem. Can you think of any reason why you'd need to do sizeof('a')?

[SameerThigale]

*
*

Also he says that characters occupy the right most seven bytes of any 8-bit byte
How can this be true and what about the first bit?

*
*

[helios]

Characters (declared, and hereinafter called, char) are chosen from the ASCII set; they occupy the rightmost seven bits of an 8-bit byte. It is also possible to interpret chars as signed, 2’s complement 8-bit numbers.

It's talking about the the ASCII character set, not about characters themselves. ASCII only needs 7 bits.

the right most seven bytes of any 8-bit byte

Don't confuse bytes and bits. They're very different things.

[SameerThigale]

But what about the first bit is my question?

[zb0S216C]

To understand High/Low-order bytes/bits, consider int as an example. int is 4 bytes in length. The 1^st byte is the low-order byte, whereas the 4^th byte is the high-order byte. This is the same for bits. For example, still using the int example, the 1^st bit is the low-order bit, whereas the 32^nd bit is the high-order bit.

Note that a Nibble (or Nyble) is 4 bit's in length. 2 nibbles make a byte. The lower-order nibble is the first 4 bits. The last 4 bits is the higher-order nibble.

_Wazzak

[SameerThigale]

@framework:
...The 1st byte is the low-order byte, whereas the 4th byte is the high-order byte...

What about the bytes in between them?

[zb0S216C]

I do believe that there's no name for them; they're just the middle bytes.

_Wazzak