Answer 1

A copy constructor is an easy way to copy data from one object to anther of the same type without coping the references.

copy constructor of a class called Person should have a parameter of Person class :

public Person(Person p){
this(p.getAge());
}

Below is an example :

class Person{
private int age;

public Person(int age){
this.age = age;
}

// * Copy constructor *
public Person(Person p){
this(p.getAge());
}

public void setAge(int age){
this.age = age;
}

public int getAge(){
return age;
}
}

public class Program
{
public static void main(String[] args) {

Person p1 = new Person(17);
Person p2 = new Person(p1);

p1.setAge(25);

System.out.println("p1 age = " +p1.getAge());

System.out.println("p2 age = " +p2.getAge());

}
}