c - Is "char" a special type of integer variable?

Question

I recently came across a statement saying that "char" type in C is really a special form of integer – one that stores the ASCII code numbers which represent characters and symbols.

How far is this valid? This leads to another question that - Can the char type really be categorized as an integer in C?

Answer 1

Yes, in C, char is considered an integer type. It's required to have a minimum of 8 bits. The equivalent between a char and a byte of storage is fairly explicit, not just something that usually happens. For example, (C99, §5.2.4.2.1/1):

number of bits for smallest object that is not a bit-field (byte)
CHAR_BIT                                            8

So, a char always occupies exactly one byte, which must be a minimum of 8 bits. If it's larger, it still occupies exactly one byte -- but that byte happens to be larger than 8 bits.

As far as holding ASCII codes goes, that's frequently true, but not necessarily the case. On something like an IBM mainframe, it'll probably hold EBCDIC codes instead. On more common machines, "ASCII" happens more or less incidentally, but when encoding non-English characters, you'll quickly find that it's not really storing ASCII. It's typically storing ISO 8859/x, or perhaps Unicode UTF-8.