public class Person implements Comparable {

private String firstName;

private String lastName;

private int age;

public Person() {

firstName = "John";

lastName = "Doe";

age = 0;

}

public Person(String f, String l, int a){

this.firstName = f;

this.lastName = l;

this.age = a;

}

public int compareTo( Object o) {

Person p = (Person) o;

return age - p.age;

}

public boolean equals( Object o){

boolean areEqual = false;

// older version of java ( ! (o instanceof Person))

if (( o == null ) || ( this.getClass() != o.getClass()))

areEqual = false;

else

{

Person p = (Person)o;

areEqual = (firstName.equals(p.firstName)) &&

(age == p.age) &&

(lastName.equals(p.lastName));

}

return areEqual;

}

}