this keyword in java

this keyword: Java define “this” keyword, that can be used inside any method to refer the current object.  “this” is always a reference to the object on which method was invoked.  “this” reference is implicitly used to refer to both the instance variables and methods of current object.

Example 1:

class Box

{

            int len,dep,hei;

            Box(int len,int dep, int hei)

            {

            this.len=len;

            this.dep=dep;

            this.hei=hei;

            }

            int volume()

            {

            return len*dep*hei;

            }

}

class this1

{

            public static void main(String[] args)

            {

                        Box obj=new Box(1,2,3);

                        int x=obj.volume();

                        System.out.println("volume="+x);

            }

}

O/P:    volume=6

            “this” reference is also used explicitly refer to the instance variables.

Example 2:

class Box

{

            int len=10;

            void method()

            {

            int len=40;

            System.out.println("local value="+len);

            System.out.println("Instance value="+this.len);

            }

}

class this2

{

            public static void main(String[] args)

            {

                        Box obj=new Box();

                        obj.method();

            }

}

O/P:    local value=40

            Instance value=10