Solved: sort descending

Sorting is an immensely crucial concept in software development. It relays to arranging data in a particular format, and for a programmer, it is vital to understand how to accurately implement sorting algorithms. One such frequently used method is sorting elements of an array in descending order. This process essentially involves arranging elements from highest to lowest or in decreasing order. This article will guide you through the solution to sort an array in descending order using Java.

In relevance to Java, it provides multiple methods to sort an array in different orders. But what do we do when we need to sort an array in descending order as there is no direct method available for it? The answer is we use the Arrays.sort() method to sort an array in ascending order and then we reverse it using the Collections.reverse() method. This way we are able to sort the array in descending order.

import java.util.Arrays; 
import java.util.Collections; 
  
public class MainClass{ 
    public static void main(String[] args) {
        Integer[] array = {12, 4, 5, 2, 5}; 
        
        // Sorting array in ascending order
        Arrays.sort(array); 
        
        Collections.reverse(Arrays.asList(array)); 
        System.out.println(Arrays.asList(array)); 
    }
} 

The above given Java program sorts the elements of an array in descending order, taking an unsorted array as an input and then printing the sorted array in console.
Breakdown of The Code
• We start by importing the required libraries, i.e., `java.util.Arrays` & `java.util.Collections`. The `Arrays` class in java.util package is a part of the Java Collection Framework and provides utility methods for arrays. It contains various static methods for sorting and searching arrays, comparing arrays, and filling array elements.
• The `Collections` class consists exclusively of static methods that operate on or return collections. It provides several general utility methods such as the Collections.reverse() method which reverses the order of the elements in the specified list.






• The 'MainClass' is the user-defined class that contains the main method.
• Inside the main method, we first create an array and initialize it with some elements.
• Then, we use the Arrays.sort() method to sort the array in ascending order.






• Subsequently, we reverse the array using the Collections.reverse() method in order to obtain the elements in descending order.
• Eventually, we print the sorted (i.e., in descending order) array.
Key Java Libraries For Sorting 
Java offers a host of libraries and methods that make implementing sort operations a breeze. Certain key ones are:

`java.util.Arrays`: This is one of the most commonly used Java library for array operations. It provides a wide range of utility methods for Arrays, including sort, binary search, comparison, fill, hash code, etc.
`java.util.Collections`: This is an auxiliary class that operates on collections and provides utility methods for collection manipulation.

Understanding these key libraries and methods is fundamental to implementing sorting operations in Java. Also, it's beneficial to know these to improve the efficiency of your code.