Pointer to constant points to a value that does not change and is declared as:

const type * name

type is data type

name is name of the pointer

e.g: const char *p;

pointer to constant can not be used to change the value being pointed to. Therefore:

char ch = ‘A’;

const char *p = &ch;

*p = ‘B’;

is not allowed. The program will throw an error.

Pointer Constant (or constant pointer) is a pointer which you don’t want to be pointed to a different value. That is, the location stored in the pointer can not change. We can not change where the pointer points. It is declared as:

type * const name

type is data type

name is name of the pointer

eg: char * const p

Since the location to which a const pointer points to can not be changed, the following code:

char ch1 = ‘A’;

char ch2 = ‘B’;

char * const p = &ch1;

p = &ch2;

will throw an error since address stored in p can not be changed.