What does “unsigned” mean when it is in itself?

Question

I came across some C code that has "unsigned" declaring a variable by itself, for example:

unsigned crc = 0; 

I think this is very strange, because I would expect an explicit variable type here. I am surprised that there are no warnings or compiler errors (MDK-Lite 5.12).

So, is it really, and what variable does it produce?

Answer 1

From specification C , section 6.7.2:

- unsigned or unsigned int

The value is unsigned , if no type is specified, the default should be unsigned int . Therefore, the entry unsigned a same as unsigned int a .