Example

int w; // w is an integer variable

int * z=&w; // z is a pointer to int; we assign to it an address of int variable w

If we write:

w = *z;

(that we could read as: " w is equal to value, pointed by z "), variable w would take the value 25, since z is 1776, and the value pointed by 1776 is 25.

You must clearly differentiate that the expression z refers to the value 1776, while *z (with an asterisk * preceding the identifier) refers to the value stored at address 1776, which in this case is 25.

A pointer may be assigned the value 0 (called the NULL pointer). The NULL pointer is used for initializing pointers. NULL is a standard (predefined) C++ constant.

Дата добавления: 2014-01-11