混淆了Java链表问题的值

Question

i'm trying to mix up the values of my linked list using Collections.shuffle but i always get the same order every time this is the code who supposed to display and mix up my list of Card :

public Deck(int nbBox) {
    this.cardList = new LinkedList<Card>();
    Collections.shuffle(cardList);
    for (int i = 0; i < nbBox; i++) {
      for (Color col : Color.values()) {
        for (Value val : Value.values()) {
          cardList.add(new Card(val, col));
        }
      }

    }

  }

Answer 1

this.cardList = new LinkedList<Card>();
    Collections.shuffle(cardList);

you were shuffling an empty list.

try to move the shuffle() line to the end of your method.

Answer 2

you should first implement your cardList before being able to shuffle it

public Deck(int nbBox) {
    this.cardList = new LinkedList<Card>();
    for (int i = 0; i < nbBox; i++) {
      for (Color col : Color.values()) {
        for (Value val : Value.values()) {
          cardList.add(new Card(val, col));
        }
      }   
    }
  Collections.shuffle(cardList);     
}