Java Inner Classes Training

About Java Inner Classes Training

Objectives of the Course

Pre Requisites

In this chapter, You will learn

• Definition of inner class
• Syntax to define inner class
• Types of inner classes
  • Static (Nested)
  • Non-static (Member)
  • Method Local
  • Anonymous
• Inner class name change after compilation
• Need of inner class
• Allowed  modifiers
• Type of members allowed in inner class
• Executing inner class using java command
• Instantiating inner class
• Executing inner class members
• Accessing inner class members from outer class and outside of outer class.
• Accessing outer class members from inner class
• Syntax to differentiate outer class members from inner class members if both have same name.
• Sample projects to understand need of Inner classes using AWT, Applet, Swing

By the end of this chapter- you will identify the correct usage and appropriate situation to use all types of inner classes.

Interview Questions

By the end of this chapter you answer all below interview questions

• What is an Inner Class?
• What is the need of Inner Classes?
• What are the advantages of Inner Classes?
• What are disadvantages of using Inner Classes?
• What are the different types of Inner Classes?
• If you compile a file containing Inner Class how many .class files are created and what are all of them accessible in usual way?
• Can we create inner class name with outerclass name or package name?
• What is static member class?
• What are Inner Classes?
• Which modifiers can be applied to the Inner Class?
• Does a static nested class have access to the enclosing class’ non-static methods or instance variables?
• How to access the inner class from code within the outer class?
• How to create an inner class instance from outside the outer class instance code?
• How to refer to the outer this i.e. outer class’s current instance from inside the inner class?
• Can the method local inner class object access method’s local variables?
• Can a method local inner class access the local final variables? Why?
• Which modifiers can be applied to the method local inner class?
• Can a local class declared inside a static method have access to the instance members of the outer class?
• Can a method which is not in the definition of the super class of an anonymous class be invoked on that anonymous class reference?
• What are different types of anonymous classes?
• Can an anonymous class define method of its own?
• Can an anonymous class implement multiple interfaces directly?
• Can an anonymous class implement an interface and also extend a class at the same time?
• How can we access local class or anonymous inner class specific members from outer class?
• Is it allowed to create inner class in interface?
• Is it allowed to create inner interface in class?
• Is it allowed to extend inner class from other class or interfaces?