Java How To: Shuffle a List/Array

This is a simple way of how to shuffle an array or a list in Java, using Collections.shuffle(<List>);

There's 2 methods:


public static void shuffle(List list);

public static void shuffle(List list, Random rnd);

Usefull Link: http://docs.oracle.com/javase/1.4.2/docs/api/java/util/Collections.html#shuffle(java.util.List)

You can use ArrayList(), or any other struct that extends <List>

You can found them here: http://docs.oracle.com/javase/6/docs/api/java/util/List.html

// Create the list
List list = new ArrayList();

// Shuffle the list - You will lose the older order
Collections.shuffle(list);

// ---------- SHUFFLE ARRAY ------------

// Create an array
String[] array = new String[20];

// Add elements

// Convert Array to List
List<String> aux = Arrays.asList(array);

// Shuffle the array
Collections.shuffle(aux);

// Convert the list to array again
array = aux.toArray();