Question

How to shuffle a list in Java

Answer 1

import java.util.List;
import java.util.Arrays;
import java.util.Random;

public class MyClass
{
    public static<T> void ShuffleList(List<T> list) {
        Random random = new Random();
 
        for (int i = list.size() - 1; i >= 1; i--) {
            int j = random.nextInt(i + 1);
 
            T obj = list.get(i);
            list.set(i, list.get(j));
            list.set(j, obj);
        }
    }
 
    public static void main(String[] args)
    {
        List<Integer> list = Arrays.asList(0, 1, 2, 3, 4 ,5 ,6 ,7, 8, 9);
 
        ShuffleList(list);
 
        System.out.println(list);
    }
} 
 
 
 
 
/*
run:
 
[2, 7, 8, 1, 0, 9, 3, 4, 5, 6]
 
*/

 

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Answer 2

import java.util.List;
import java.util.Arrays;
import java.util.Collections;

public class MyClass
{
    public static void main(String[] args)
    {
        List<Integer> list = Arrays.asList(0, 1, 2, 3, 4 ,5 ,6 ,7, 8, 9);
 
        Collections.shuffle(list);
 
        System.out.println(list);
    }
} 
 
 
 
 
/*
run:
 
[6, 1, 5, 9, 0, 8, 2, 4, 3, 7]
 
*/

 

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