Can someone explain object cloning,what is given in the comments in the code- -https://code.sololearn.com/cKO7sy0uisr4/?ref=app

Question

Object cloning-https://code.sololearn.com/cKO7sy0uisr4/?ref=app

Answer 1

Object ref1=ref.clone();
Emp ref2=(Emp)ref1;

//Line 1- A reference variable of Object type is initialized with a copy of your object of "Emp" class.

It is legal since the Object class is the Super class of every class you create in Java.

//Line 2- Your Object type variable which hold the copy of your "Emp" object is type casted to "Emp" so that it can be stored by a "Emp" type reference.

Answer 2

Why should I do downcasting(line 2) ,whats the use

Answer 3

Can't I put ref1.empname just like that?

Answer 4

Because your ref1 is of Object type so you cannot directly assign it to "Emp" without casting. You will probably get a type mismatch error or something.

Answer 5

because Object.clone() returns Object not Emp
but Object has not properties like Salary

EDIT2:
your attempt is interesting, but then you can't clone Emp object in other class outside Emp. Solution is implement clone() in Emp

public class Emp implements Cloneable{
//..
public Emp clone() {
Emp emp = null;
try {
emp = (Emp) super.clone();
} catch (CloneNotSupportedException e) {
System.out.println("cloning not supported");
}
return emp;
}
public static void main(String[] args) {
//..
Emp ref2 = ref.clone();
} }