Review of the Object class

This sort of activity is very common in programming. You will see it a lot in the future. Notice that no new objects were created; but different reference variables were used for already-existing objects.

In Java, there is a pre-defined class that is the ultimate ancestor of all other classes. This class is called Object. When you define a class of your own like this:

class MyNewClass
{

}

You are actually defining a child of the Object class. The following is the exact equivalent of the above:

class MyNewClass extends Object
{

}

Every class in Java — your own and every class in every library — descends from Object. This will be important to remember when you get to graphical user interfaces.