Different types of Comparator Techniques in Java

Comparator Techniques in Java

Java provides robust mechanisms for comparing objects through the Comparable and Comparator interfaces.

a. Using Comparable Interface

The Comparable interface allows objects of a class to be compared using their natural order.

Example:

public class Product implements Comparable<Product> {
    private String name;
    private double price;
    public Product(String name, double price) {
        this.name = name;
        this.price = price;
    }
    @Override
    public int compareTo(Product other) {
          return Double.compare(this.price, other.price);
    }
}

b. Using Comparator Interface

For custom comparison logic, the Comparator interface is more flexible.

Example:

import java.util.*;

Comparator nameComparator = (p1, p2) -> p1.getName().compareTo(p2.getName());
List products = Arrays.asList(new Product("Apple", 1.2), new Product("Banana", 0.5));
products.sort(nameComparator);

Best Practices

• Use Comparable for natural ordering.

• Use Comparator for multiple sorting criteria.