Objective-C Programming: The Big Nerd Ranch Guide

description and %@

In calls to NSLog(), you have been using the token %@ to get an object to describe itself. The %@ token sends a description message to the object pointed to by the corresponding variable.

The description method returns a string that is a useful description of an instance of the class. It is an NSObject method, so every object implements it. The default NSObject implementation returns the object’s address in memory as a string.

However, a memory address is often not the most useful way to describe an instance. A class can override description:. For example, NSDate overrides description to return the date/time that the instance holds. NSString overrides description to return the string itself.

In BNREmployee.m ...