Java 6 Illuminated: An Active Learning Approach, 2nd Edition

It’s important to understand that an object reference and the object data

are different: The object reference represents the memory location, and the

object data are the data stored at that memory location. Notice in Figure

3.1 that the object references, independenceDay, graduationDate, and

defaultDate, point to the locations of the object data.

3.3 Calling Methods

Once an object is instantiated, we can use the object by calling its methods.

As we mentioned earlier, the authors of classes publish their API so that their

clients know what methods are available and how to call those methods.

Figure 3.2 illustrates how calling a class method alters the ...