const and pointers in C

Question

The use of const with a pointer can make the pointee not modifiable by dereferencing it using the pointer in question. But why neither can I modify what the pointer is not direc

Answer 1

ptr +2 simply has the same type as ptr namely is a pointer to a const object.

Pointer arithmetic supposes that the object that is pointed to is an array of all the same base type. This type includes the const qualification.