signed variables need to be specified?

[b1gzz]

I'm reading a C++ book, and I'm on the part of the variables. My question is: do we need to specify a variable to signed or the compiler does it by default?

Thanks

[mutexe]

have a look at the table on this page:
http://www.cplusplus.com/doc/tutorial/variables/
and the comment directly below it.

[Stewbond]

variables are always signed by default unless explicitly stated otherwise.

[b1gzz]

Thank you very much.