Classes in Java

Class is a blueprint of object. It can also be defined as a collection of related data and relevant methods. For instance, class could be like the blueprint of a house, it has no physical reality but rather a proposal and room for alterations.

Syntax of Class

/*Modifiers are not compulsory. 'class' is a reserved keyword and classname is the name of the class.*/



[Modifier] class [classname] 


{

Logic of Class

}

/*All the logic of the class will be between these two curly brackets.*/
   

Types of Classes

● Top level class

● Class within Class

Top Level Class

These type of classes are independent classes, which are not defined within other classes and thus called Top Level classes. Other classes may or may not be defined inside top level classes.

Class within Class

There could be three such classes:

● Member class

● Local class

● Anonymous class

Member Class

A Member class is one which is defined inside another class. Member classes are of two types:

➯ Static member class

A member class which is defined with static keyword. For example:

class A
{
	static class B
	{
	}
}
  

➯ Non Static member class

A member class which is defined without static keyword. For example:

class A
{
	class B
	{
	}
}

  

Local Class

A local class is one which is defined inside method

    class A
{
	m()
	{
		class B
		{
		}
	}
	
}

   

Anonymous class

Anonymous class, as the name suggests is defined without name.

References : Oracle share on :        :