This keyword in Java programming language

This keyword in Java programming language

In this tutorial, we will discuss the concept of “This” keyword in Java programming language.

This keyword

 Using this with a field

“This” keyword is used as a reference to the current object that is an instance of the current class.

“This” reference to the current object is useful in situations where a local variable hides or shadows a field with the same name.

Program 1

public class thisis{
int id;
String name;

thisis(int id,String name){
id=id;                                          // not use this keyword
name=name;                             // not use this keyword
}
void display()
{
System.out.println(id+” “+name);
}

public static void main(String args[]){

thisis obj=new thisis(7,”vannan”);
thisis obj1=new thisis(8,”varathan”);
obj.display();
obj1.display();
}

}

output – to int – 0
             – to String – null    

program 2

public class thisis{
int id;
String name;

thisis(int id,String name){   // this is constructor
this.id=id;                            // this keyword index current constructor
this.name=name;
}
void display()
{
System.out.println(id+” “+name);
}

public static void main(String args[]){

thisis obj=new thisis(7,”dffffff”);
thisis obj1=new thisis(8,”dff9888″);
obj.display();
obj1.display();
}

}

Example 3

Nlo need the this keyword

class School
{
int id;
String name;
School(int id1,String name1)
{
name=name1;
id=id1;
}
void show()
{
System.out.println(id+” “+name);
}

public static void main(String args[])
{
School s1=new School(111,”vannan”);
School s2=new School(222,”varathan”);
s1.show();
s2.show();
}
}

this keyword was used to invoke current class method.

 

Example

class mystudent
{
void showresult()
{
System.out.println(“you got very good pass”);
}

void marks()
{
showresult();
}
void display()
{
showresult();
}

public static void main (String args[])
{
mystudent s=new mystudent();
s.display();
}
}

 

 

 

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