[Top Interview Question]Use of Comparator for Custom Sorting in Java

Problem Statement

Scenario: You have a list of users, and you need to sort them based on their name and age. The requirement is that the list should first be sorted alphabetically by name, and if two users have the same name, they should be sorted by their age in ascending order.

Sorting objects based on custom criteria is a common requirement in Java applications. While Java provides the Comparable interface for natural ordering, the Comparator interface is more flexible when you need to define multiple or dynamic sorting criteria. In this article, we'll explore how to use Comparator effectively for custom sorting.

Why Use Comparator?

The Comparator interface in Java allows you to define custom sorting logic outside the natural ordering defined by the Comparable interface. The key benefits of using Comparator include:

• Flexibility: Allows sorting based on various fields without modifying the original class.
• Multiple Sorting Criteria: Enables dynamic sorting based on multiple fields in different orders (ascending/descending).
• Ease of Use: Java 8’s lambda expressions and Comparator methods (thenComparing(), reversed(), etc.) make custom sorting easy and…