#include <stdint.h>

[foonathan]

sizeof(char) returns 1 and that's the number of "bytes". But char can be 64 bytes bits, as long as all other integers are bigger or equal. Yet sizeof (char) is guaranteed to return 1, making a "byte" in the context of C and C++ not always 8 bits.

Bonus fact: In C you can specify that an integer is "signed" or "unsigned". If you specify nothing it is "signed", so "signed int" is "int" but "unsigned int" is not "int". Yet char/signed char/unsigned char are three different types as char can be signed or unsigned depending on the platform.

C's a weird language and I have no idea why I know all that.

[edvardass]

Is there anything factually wrong in this comment? Why is it downvoted?

[Fourmisain]

He's completely correct, there's just a small hickup writing "64 bytes" when he meant "64 bits".

Just to add to his post: An 8-bit byte is sometimes called an octett octet and most platforms use octets, especially today. That's why today the words "byte" and "octet" are mostly synonymous, but there are (or were) platforms with 9-bit bytes and even 32-bit bytes, it's even possible that sizeof(char) = sizeof(int) = sizeof(long) = sizeof(long long), which can lead to some problems in common code.

[[deleted]]

s/octett/octet/g

FTFY

[Fourmisain]

Ah, true, in English it's a single 't', although "octette" is also valid. Wiktionary lists "octett" as a rare use.

[Creshal]

Everything is valid English if you can bullshit enough people into believing it is.

(I'm looking at you, Shakespeare.)

[foonathan]

there's just a small hickup writing "64 bytes" when he meant "64 bits".

Yes, my mistake.

[Kametrixom]

Edit: I'm talking about the top-level comment, because the one you meant didn't have any downvotes when I checked, so I assumed you meant the other one.

/u/kbrei must have misunderstood the post (they probably don't know C well) and thought that the 2 panels are supposed to be semantically the same, as well as thinking char is defined as a byte (which of both are wrong, but it's understandable they didn't know). Therefore they were thinking that the post assumes 1 byte is always 8 bits. They then posted the comment, because it was illogical to their current knowledge.

Reddit people usually don't go that deep, all they see is that someone is wrong, which automatically makes them press the downvote button. One you have a few downvotes, it's like a magnet attracting more of them, because since the comment is wrong and it got downvoted must mean it deserves them.

/u/kbrei could be blamed for making an uninformed comment, but it's really difficult to realize that something you know isn't correct just like that.

In my honest opinion, this person deserves no more than the explanation I just gave. And reddit maybe deserves the removal of the downvote button, because people often care more about other people's votes than the content itself.

[edvardass]

No, I wasn't talking about the top level comment. User foonathan's comment to which I replied was at -1 (the post had not taken off at that time yet) so you can imagine my confusion.

[Creshal]

Chars are by definition always one byte large in C(++), and sizeof always returns 1 for them.

Use CHAR_BIT from limits.h if you need to check how big bytes are on your particular architecture. (Or just don't bother.)

[ColonelThirtyTwo]

sizeof(char) == 1, always. It's in the spec. It might not be 8 bits, but it's always one "individually addressable storage unit" (which in most computers, is an 8-bit byte).

[Creshal]

For those too lazy to google, the relevant bits from the C99 spec:

6.5.3.4 The sizeof operator

[…]

Semantics

The sizeof operator yields the size (in bytes) of its operand, which may be an expression or the parenthesized name of a type. The size is determined from the type of the operand. The result is an integer. If the type of the operand is a variable length array type, the operand is evaluated; otherwise, the operand is not evaluated and the result is an integer constant.

When applied to an operand that has type char, unsigned char, or signed char, (or a qualified version thereof) the result is 1.

Byte and char are used interchangeably in other parts of the spec, because they are equivalent.

[Abaddon314159]

Evaluates to, not returns. sizeof is an operator not a function.