C++ Primer Plus, Fourth Edition

Pointers, Arrays, and Pointer Arithmetic

The near equivalence of pointers and array names stems from pointer arithmetic and how C++ handles arrays internally. First, let's check out the arithmetic. Adding 1 to an integer variable increases its value by 1, but adding 1 to a pointer variable increases its value by the number of bytes of the type to which it points. Adding 1 to a pointer to double adds 8 to the numerical value on systems with 8-byte double, whereas adding 1 to a pointer-to-short adds 2 to the pointer value if short is 2 bytes. Listing 4.14 demonstrates this amazing point. It also shows a second important point: C++ interprets the array name as an address.

Listing 4.14. addpntrs.cpp

// addpntrs.cpp--pointer addition #include <iostream> ...