What is the difference between const char *p, char * const p and const char * const p?

const char *p - This is a pointer to a constant character. You cannot change the value pointed by p, but you can change the pointer p itself.

*p = 'S' is illegal.
p = "Test" is legal.

Note - char const *p is the same.


const * char p - This is a constant pointer to non-constant character. You cannot change the pointer p, but can change the value pointed by p.

*p = 'A' is legal.
p = "Hello" is illegal.


const char * const p - This is a constant pointer to constant character. You cannot change the value pointed by p nor the pointer p.

*p = 'A' is illegal.
p = "Hello" is also illegal.