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keyword : this

'this' is used for pointing the current class instance. It can be used with variables or methods. Look into the following example:

class Test{

private int i=10;public void m(){

System.out.println(this.i);}

}In the above code this is used for the current instance. Since this is instanceof a class it cannot be used inside a static method.keyword : super

'super' is used for pointing the super class instance. See the following example.

class A{

int k = 10;}class Test extends A{

public void m(){

System.out.println(super.k);}

}In the above example the super keyword is used for accessing the super class var

iable.

Example 2:

package InnerclassDemo;

public class venkatDoubt {

String s = "siva";void method1(){

System.out.println(" this my first method");

} class innerClassEx {String s="tea";void method2(){

System.out.println(" this my second method");

}void hh() {

String s="oooo";System.out.println("hi :" + s +"...."+this.s +"..."+venk

atDoubt.this.s);}

class innerInnerClass2{void jj(){

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}}

}public static void main(String args[]){

venkatDoubt.innerClassEx inner =new venkatDoubt().new innerClassEx();inner.hh();inner.method2();

}

}

output:hi :oooo....tea...sivathis my second method

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Anonymous Inner Classes in Java

If an inner class has been declared without a name and within a code block (typically within the body of a method) then such an inner class is called an anonymous inner class. Since such an inner class doesn't have a name associated, so it'll be accessible only at the point where it is defined.

Example:

class Popcorn {public void pop() {

System.out.println("popcorn");}

}

class Food {public static void main(String args[]){Popcorn p = new Popcorn() {

public void pop2() {System.out.println("anonymous popcorn");

}};p.pop();}

}

output:

popcorn

---------------------------------------------------------------------------------------

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A static java inner class cannot have instances.A non-static java inner class can have instances that belong to the outer class.

package InnerclassDemo;

class StaticmethodInnerClass {

class Employee{

int grossSalary(int basicSalary){

return basicSalary+2000;}

}

static class Worker{

int wages(int workDays)

{return workDays*200;

}}

public static void main(String args[])

{

// Create object to inner class

StaticmethodInnerClass.Employee innerEmp=new StaticmethodInnerClass().new Employee();

System.out.println("Employee GrossSalary :"+innerEmp.grossSalary(15000));

// Create object to static inner class

StaticmethodInnerClass.Worker innerWorker=new StaticmethodInnerClass.Worker();

System.out.println("Worker wages :"+innerWorker.wages(20));

}}

output:Employee GrossSalary :17000Worker wages :4000