Question

Possible Duplicate:
const int = int const?

What is the difference between these combination of keywords ?

const int*

int const*

int* const

Is it possible to modify the value of a constant by accessing its address using a pointer ?

Answer 1

In general:

   const T            ===               T const

and

   const T *          ===               T const *

but

   T * const

makes the pointer constant, but not necessarily the contents of T.

    const T * const      ===         T const * const

will make both the contents of T and the pointer itself constants.

As for changing the contents of a const: you shouldn’t be able to, but the compiler/OS/CPU don’t try too hard to stop you, so you get what is colloquially called “undefined behaviour,” which is a nice way of saying “random crashes on some systems”