Java Program to Shuffle the Elements of a Collection

In this article, we will understand how to shuffle the elements of a collection. The Collection is a framework that provides architecture to store and manipulate the group of objects. Java Collections can achieve all the operations that you perform on a data such as searching, sorting, insertion, manipulation, and deletion.

Below is a demonstration of the same −

Suppose our input is −

Input list: [Java, program, is, fun, and, easy]

The desired output would be −

The shuffled list is:
[is, easy, program, and, fun, Java]

Algorithm

Step 1 - START
Step 2 - Declare an arraylist namely input_list.
Step 3 - Define the values.
Step 4 - Using the function shuffle(), we shuffle the elements of the list.
Step 5 - Display the result
Step 6 - Stop

Example 1

Here, we bind all the operations together under the ‘main’ function.

import java.util.*;
public class Demo {
   public static void main(String[] args){
      ArrayList<String> input_list = new ArrayList<String>();
      input_list.add("Java");
      input_list.add("program");
      input_list.add("is");
      input_list.add("fun");
      input_list.add("and");
      input_list.add("easy");
      System.out.println("The list is defined as:" + input_list);
      Collections.shuffle(input_list, new Random());
      System.out.println("The shuffled list is: \n" + input_list);
   }
}

Output

The list is defined as:[Java, program, is, fun, and, easy]
The shuffled list is:
[is, Java, fun, program, easy, and]

Example 2

Here, we encapsulate the operations into functions exhibiting object oriented programming.

import java.util.*;
public class Demo {
   static void shuffle(ArrayList<String> input_list){
      Collections.shuffle(input_list, new Random());
      System.out.println("The shuffled list is: \n" + input_list);
   }
   public static void main(String[] args){
      ArrayList<String> input_list = new ArrayList<String>();
      input_list.add("Java");
      input_list.add("program");
      input_list.add("is");
      input_list.add("fun");
      input_list.add("and");
      input_list.add("easy");
      System.out.println("The list is defined as:" + input_list);
      shuffle(input_list);
   }
}

Output

The list is defined as:[Java, program, is, fun, and, easy]
The shuffled list is:
[fun, and, Java, easy, is, program]