Inheritance - Java Software Solutions: Foundations of Program Design - page 448

LISTING 9.3
//********************************************************************
// Dictionary.java Author: Lewis/Loftus
//
// Represents a dictionary, which is a book. Used to demonstrate
// inheritance.
//********************************************************************
public class Dictionary extends Book
{
private int definitions = 52500;
//-----------------------------------------------------------------
// Prints a message using both local and inherited values.
//-----------------------------------------------------------------
public double computeRatio ()
{
return ( double ) definitions/pages;
}
//----------------------------------------------------------------
// Definitions mutator.
//----------------------------------------------------------------
public void setDefinitions ( int numDefinitions)
{
definitions = numDefinitions;
}
//----------------------------------------------------------------
// Definitions accessor.
//----------------------------------------------------------------
public int getDefinitions ()
{
return definitions;
}
}
declared with protected visibility, a derived class can reference it. And protected
visibility allows the class to retain some encapsulation properties. The encapsula-
tion with protected visibility is not as tight as it would be if the variable or method
were declared private, but it is better than if it were declared public. Specifically, a