Const in C++

from C++ FAQ

You have to read pointer declarations right-to-left.

• const Fred* p means "p points to a Fred that is const" — that is, the Fred object can't be changed via p.
• Fred* const p means "p is a const pointer to a Fred" — that is, you can change the Fred object via p, but you can't change the pointer p itself.
• const Fred* const p means "p is a const pointer to a const Fred" — that is, you can't change the pointer p itself, nor can you change the Fred object via p.

-Kalyan