8.8. Pointer Expressions and Pointer Arithmetic

This section describes the operators that can have pointers as operands and how these operators are used with pointers. C++ enables pointer arithmetic—a few arithmetic operations may be performed on pointers. Pointer arithmetic is appropriate only for pointers that point to built-in array elements.

A pointer may be incremented (++) or decremented (--), an integer may be added to a pointer (+ or +=) or subtracted from a pointer (- or -=), or one pointer may be subtracted from another of the same type—this particular operation is appropriate only for two pointers that point to elements of the same built-in array.

Assume that int v[5] has been declared and that its first element is at memory location 3000. Assume that pointer vPtr has been initialized to point to v[0] (i.e., the value of vPtr is 3000). Figure 8.15 diagrams this situation for a machine with four-byte integers. Variable vPtr can be initialized to point to v with either of the following statements (because a built-in array’s name evaluates to the address of its zeroth element):

Fig. 8.15. Built-in array v and a pointer variable int *vPtr that points to v.