public class ex2 {

int id;

String name;

String city;

ex2(){

System.out.println("default constructor invoked");

}

ex2(int id,String name){

this();//it is used to invoked current class constructor.

this.id = id;

this.name = name;

}

ex2(int id,String name,String city){

// constructor chaining

//Call to this() must be the first statement in constructor.

this(id,name);//now no need to initialize id and name

this.city=city;

}

void display(){System.out.println(id+" "+name+" "+city);}

public static void main(String args[]){

ex2 e1 = new ex2(111,"karan");

ex2 e2 = new ex2(222,"Aryan","delhi");

e1.display();

e2.display();

}

}

/*output

*default constructor invoked

default constructor invoked

111 karan null

222 Aryan delhi

*/