c - Is char signed or unsigned by default?

Question

In the book "Complete Reference of C" it is mentioned that char is by default unsigned.

But I am trying to verify this with GCC as well as Visual Studio. It is taking it as signed by default.

Which one is correct?

Answer 1

The book is wrong. The standard does not specify if plain char is signed or unsigned.

In fact, the standard defines three distinct types: char, signed char, and unsigned char. If you #include <limits.h> and then look at CHAR_MIN, you can find out if plain char is signed or unsigned (if CHAR_MIN is less than 0 or equal to 0), but even then, the three types are distinct as far as the standard is concerned.

Do note that char is special in this way. If you declare a variable as int it is 100% equivalent to declaring it as signed int. This is always true for all compilers and architectures.