
692 CHAPTER 10 Object-Oriented Programming,Part 3: Inheritance,Polymorphism,and Interfaces
declared abstract, then the class is not abstract and we can instantiate
objects of that subclass.
Example 10.16 shows the Circle class, which inherits from the Figure class
and adds a radius instance variable. In the overloaded constructor, we pass
the startX, startY, and startColor parameters to the constructor of the Figure
class (line 34). On lines 54–63, the Circle class implements the draw
method. We get the (x, y) coordinate and the color for the circle by calling
the accessor methods of the Figure class because the x, y, and color instance
variables are ...