this keyword and final keyword with examples

2. Introdraction of this keyword
• “ this “keyword is the refer to the
current object.
• This keyword is used to the pointout the
current object.

3. This keyword
 The this keyword is refers to the current class
object.
 The this keyword is use the point out the
current class object.
 Java objects include a data member named
a THIS , which is actually a reference to the
current object.
 The THIS keyword is useful if you need to
refer to the current object.

4. Simple example of This
keyword
class student
{
int r_no;
String name;
student (int r,String n)
{
this.r_no = r ;
this.name = n ;
System.out.println (r_no:+name) ;
}

5. public static void main (String args [] )
{
student s1 = new student ( 1 ,” Kinjal ”);
Student s2 = new student ( 2 ,” Veena ”);
Student s3 = new student ( 6 ,” dhariya ”);
}

6.  Now here by using this keyword “THIS” like
this.r_no we mean that variable r_no of the
invoking object.
student s1 = new student ( 1 ,” Kinjal ”);
student ( int r , String n )
{
this . r_no = r ; //means s1.r_no
this . name = n ; // means s1.name
System . Out . println (r_no:+name) ;
}

7. Output:
1 : Kinjal
2 : veena
6 : dhariya

8. Final Keyword

9. final keyword
 Java’s FINAL keyword has slightly different
meanings depending on the context,but in
general it say
“ This cannot be changed” or ”This is final”
 Use of “final” in java is synonymous to use of
“Const” in c++.
 The following section discuss the three places
where final can be used for:
Data
method
classes

10. final Data
 Java provides you way to fix the value of any
variable by using the “final” keyword when
you declare it..
For example:
final int a = 100;
final int b=4;
 The final keyword specifies that the value of a
variable is final and must not be change.
 This makes it easy to see which variables are
defined as constant value.

11. final method and class
 The final keyword use for more then one
purpose in java programing.
 It can be userd with class and member.
 When the final keyword used with a class,
that prevents the class from main
inherintance,you cannot inherit class

12. Simple program of using the
final keyword
class abc
{
final void show ()
{
system . out .println (“Hi”) ;
}
}

13. class abc1 extends abc
{
public void show ();
{ Error
system . out . Println (“ Hello”) ; Display
}
}
class test
{
public static void main (String args [ ] )
{
abc1 .a1 = new abc1 () ;
a1 . show () ;
}
}

14. Thank you