ch01_basics

1. Classes, static classes, inner classes

• *.java file must have exactly one public class, its name must be equal to filename

Inner classes

• see: www.tutorialspoint.com/java/java_innerclasses
  • in Java can't exist class with private modifier - except inner class

Inner class

• to creation new instance of inner class must exist instance of outer class
• has access to attributes and methods of outer class
• it can exist inner class inside method - its instance is available only inside the method

Anonymous Inner class

• declaration and instance creation is at the one place (in single command) - class definition is at the another place as abstract class or interface
• has no access to attributes and methods of abstract class
• can be used as method input argument - abstract method must be implemented at the usage place
• since Java 8 is possible to use lambda expressions or method reference (see next chapters of OCA and OCP parts)

Nested Static class

• is accessible without instance of outer class
• has no access to attributes and methods of outer class

Basic inheritance

• see OCP, chapter 1 Classes and objects