java.util.Collections.shuffle() Method

Description

The shuffle(List<?>, Random) method is used to randomly permute the specified list using the specified source of randomness.

Declaration

Following is the declaration for java.util.Collections.shuffle() method.

public static void shuffle(List<?> list,Random rnd)				 

Parameters

• list − The list to be shuffled.

• rnd − The source of randomness to use to shuffle the list.

Return Value

NA

Exception

UnsupportedOperationException − This is thrown if the specified list or its list-iterator does not support the set operation.

Example

The following example shows the usage of java.util.Collections.shuffle()

package com.tutorialspoint;

import java.util.*;

public class CollectionsDemo {
   public static void main(String args[]) {  
      
      // create Linked List
      LinkedList<Integer> list = new LinkedList<Integer>(); 

      // populate list
      list.add(52);  
      list.add(27);  
      list.add(14);  
      list.add(-33);

      System.out.println("List before shuffle: "+list);   

      // shuffle the list
      Collections.shuffle(list);  

      System.out.println("List after shuffle: "+list);
   }
}

Let us compile and run the above program, this will produce the following result.

List before shuffle: [52, 27, 14, -33]
List after shuffle: [14, -33, 27, 52]