General Info: Inheritance

The concept of a class makes it possible to define subclasses that share some or all of the main class characteristics. This is called inheritance. Inheritance also allows you to reuse code more efficiently. In a class tree, inheritance is used to design classes vertically. (You can use Interfaces to design classes horizontally within a class tree.) With inheritance, you are defining an "is-a" relationship (i.e. a chow is-a dog). Analysts using UML call this generalization where you generalize specific classes into general parent classes.

Java Inheritance

Simple syntax example of class inheritance.

In the following example, a terminator T-600 is-an android. 

public class Android {

}

public class T-600 extends Android {

}

Class Scope Specifiers

Private, Protected, and Public Members

In most OOP languages, private, protected, and public members have a specific scope:

• Private = Used by the defining class only. Invisible outside of the class except by friendly classes.
• Protected = Used by the defining class and descendant classes only (plus friendly classes).
• Public = Visible wherever its class can be referenced.