The keyword const specifies that you can not change the value of the variable. When it comes to pointers, we can have two types of constants.
It prevents you from changing the pointer from one memory location to another. However, you can change the contents of the pointer.
int myInt = 10; int* const pInt = &myInt; // Constant pointer int myNewInt = 20; pInt = &myNewInt; //Illegal *pInt = 30; // Legal
Pointer to a constant
It prevents you from changing the contents of the memory location. However, you can reassign the pointer to a new memory location.
int myInt = 10; const int* pInt = &myInt; // Pointer to a constant int myNewInt = 20; pInt = &myNewInt; //Legal *pInt = 30; // Illegal