Programming in Objective-C, Sixth Edition

Pointers and Memory Addresses

Before we end this discussion of pointers in Objective-C, we should point out the details of how they are actually implemented. A computer’s memory can be conceptualized as a sequential collection of storage cells. Each cell of the computer’s memory has a number, called an address, associated with it. Typically, the first address of a computer’s memory is numbered 0. On most computer systems, a cell is 1 byte.

The computer uses memory to store the instructions of your computer program and to store the values of the variables associated with a program. So if you declare a variable called count to be of type int, the system assigns locations in memory to hold the value of count while the program is executing. For example, ...