... you can construct a string that describes all sorts of information about the object, such as the fat content and calories for the cheese Danish. The description method for Cocoa’s NSArray class, ... which manages a collection of objects, provides informa-tion about the array itself, such as the number of objects it contains and descriptions of each object it contains. These descriptions, ... message to the Circle object, the dispatcher first consults the Circle class to see if it can respond to setFillColor: with its own code. In this case, the answer is no: the dispatcher discovers...