Trace the code for classes References$1$ and References$2$ using Person

$//****************//$ References$1.$java

$//$

$//$ Illustrates aliases and references

$\frac{\frac{?}{?}}{*}*****************************************************************************************************************************************************$

public class References $1$

$\{$

public static void main $($String$[]$ args$)$

$\{$

Person person $1=$ new Person $("$Rachel$",6)$;

Person person$2=$ new Person $("$Elly$",4)$;

Person person $3=$ new Person $("$Sarah$",19)$;

System.out.print In $("$InThe three original people..."$)$;

System.out.print In $($person$1+","+$ person$2+","+$ person$3)$;

$//$ Reassign people

person$1=$ person$2$;

person$2=$ person$3$;

person $3=$ person$1$;

System.out.printIn$("$

The three people reassigned..."$)$;

System.out.println $($person$1+","+$ person $2+","+$ person$3)$;

System.out.print $ln()$;

System.out.println $("$Changing the second name to Bozo..."$)$; person$2.$changeName $("$Bozo$")$;

System.out.print In $($person$1+","+$ person$2+","+$ person$3)$;

System.out.println$()$;

System.out.println $("$Changing the third name to Clarabelle..."$)$; person$3.$changeName $("$Clarabelle$")$;

System.out.printIn $($person$1+","+$ person$2+","+$ person$3)$;

System.out.print $ln()$;

System.out.printIn $("$Changing the first name to Harpo..."$)$; person$1.$changeName$("$Harpo$")$;

System.out.println $($person$1+","+$ person$2+","+$ person$3)$;

$\}$

$\}$

$\frac{\frac{?}{?}}{*}*************************************************************************************************************************************************$

$//$ References$2.$java Ilustrates references versus primitive variables

$//$

import java.util.Scanner;

public class References $2\{$

public static void main $($String$[]$ args$)$

int age$1,$ age$2,$ age$3$;

Scanner scan $=$ new Scanner$($

System.in$)$;

System.out.println $("$Enter three ages..."$)$;

age $1=$ scan.nextint$()$;

age $2=$ scan.next Int $()$;

age $3=$ scan.nextInt$()$;

$//$ Instantiate three Person objects with the ages read in

Person person $1=$ new Person $("$Rachel$",$ age$1)$;

Person person$2=$ new Person $("$Elly$",$ age$2)$;

Person person$3=$ new Person $("$Sarah$",$ age$3)$;

System.out.print $ln()$

System.out.println $("$The original three people..."$)$;

System.out.print In $($person$1+","+$ person$2+","+$ person$3)$;

$//$ Reassign ages in the int variables

age$1=$ age$2$;

age$3=$ age$2$;

$//$ Reassign the Person objects

person$1=$ person$2$;

person$3=$ person $2$ ;

System.out.println $()$;

System.out.print In $("$The changed values are..."$)$;

System.out.printIn $("$Ages $($ints$)$: $"+$ age$1+","+$ age $2+","+$ age$3)$;

System.out.println $($person$1+","+$ person$2+","+$ person$3)$;

$//$ Make some changes to the integer values and corresponding objects System.out.println $("$InChanging the second age to $99...)$; age $=99$;

person$2.$changeAge$($age$2)$;

System.out.println $("$The changed values are..."$)$;

System.out.println $("$Ages $($ints$)$: $"+$ age$1+","+$ age $2+","+$ age$3)$;

System.out.printin $($person $1+",+$ person $2+","+$ person$3)$;

System.out.print $ln()$

System.out.print In $("$Changing the first age to $100...")$;

age $1=100$;

person$1.$changeAge$($age$1)$;

System.out.println $("$The changed values are..."$)$;

System.out.println $("$Ages $($ints$)$: $"+$ age$1+","+$ age$2+","+$ age$3)$;

System.out.print In $($person$1+","+$ person$2+","+$ person$3)$; $\}\}$

$//1$ P$************************************************$

public class Person

i

private String name;

private int age;

$//$

$//$ Sets up a Person object with the given name and age.

$//$

public Person $($String name, int age$)$

$\{$

this.name $=$ name;

$\}$

this.age $=$ age;

$//$

$//$ Changes the name of the Person to the parameter newName.

$\frac{\frac{?}{?}}{-}$

public void changeName$($String newName$)$

$\{$

$\}$

name $=$ newName;

$//$

$//$ Changes the age of the Person to the parameter newAge.

$//-$

public void changeAge $($int newAge$)$

$\{$

age $=$ newAge;

$\}$

$//-$

$//$ Raturns the person's name and age as a surng.

$//-$

public String toString$()$

$\{$

return name $+"-$ Age $"+$ age;

$\}$

$\}$