What design pattern is used to determine the order of object comparison?

The Strategy design pattern is usually used to determine the order of object comparison.

It allows defining a family of comparison algorithms, encapsulating each one, and making them interchangeable.

In Java, this is often implemented through the Comparator<T> interface, which defines a method for comparing two objects.

Example:

import java.util.*;

class Person {
    String name;
    int age;
    Person(String name, int age) {
        this.name = name;
        this.age = age;
    }
}

// Strategy for comparison by age
class AgeComparator implements Comparator<Person> {
    public int compare(Person p1, Person p2) {
        return Integer.compare(p1.age, p2.age);
    }
}

// Usage
List<Person> people = Arrays.asList(new Person("Alice", 30), new Person("Bob", 25));
Collections.sort(people, new AgeComparator());

Thus, the Strategy pattern allows changing the comparison logic without modifying the object classes.