This keyword in Java

this();//need to create the constructor mandatory.this(int a,int b);

//need to create the super class parameterised constructor mandatory.

class Employee{
public int emp_Id=123;
public Employee(){
System.out.println("Default Constructor In Java");
}
public Employee(int id){
System.out.println("Parameterised Constructor In Java"+id);
}
public void display(){
System.out.println("This is display method");
}
}
class EmpInfo extends Employee{
public EmpInfo(){
this();//to call the super class constructorin sub class
int number=this.emp_Id;//to call the super class variable
System.out.println("The Value Was"+number);
this(12,34);
}
public void test(){
this.display();
}
public static void main(String args[]){
EmpInfo  emp=new EmpInfo();
EmpInfo  emp1=new EmpInfo(45);
emp.display();
}
}//class

Default Constructor In Java.

Parameterised Constructor In Java 45.

The Value Was:123

This is displaymethod.