public int compare(Person firstPerson, Person secondPerson) {
String personName1 = firstPerson.getFirstName().toUpperCase();
String personName2 = secondPerson.getFirstName().toUpperCase();
// ascending order
return personName1.compareTo(personName2);
// descending order
// return fruitName2.compareTo(fruitName1);
}
public static void displayList(Person[] persons) {
for (int i = 0; i < 4; i++) {
Person person = persons[i];
String lastName = person.getLastName();
String firstName = person.getFirstName();
int age = person.getAge();
System.out.println(lastName + ", " + firstName + ". Age:" + age);
}
System.out.println();
}