How to randomize JS and then repeat?

Question

I have my code to the point where it will randomize the deck to the point where it will never pull the same card. Once a card has been drawn it will remove it from the array. The catch is, once all of the cards has been drawn it goes to "Null" and i'd rather it just re-randomizes the deck and repeats back to the start again.

Is there anyway of doing this?

var cards = [
    'clubs-ace',
    'clubs-2',
    'clubs-3',
    'clubs-4',
    'clubs-5',
    'clubs-6',
    'clubs-7',
    'clubs-8',
    'clubs-9',
    'clubs-10',
    'clubs-jack',
    'clubs-queen',
    'clubs-king',
    'diamonds-ace',
    'diamonds-2',
    'diamonds-3',
    'diamonds-4',
    'diamonds-5',
    'diamonds-6',
    'diamonds-7',
    'diamonds-8',
    'diamonds-9',
    'diamonds-10',
    'diamonds-jack',
    'diamonds-queen',
    'diamonds-king',
    'hearts-ace',
    'hearts-2',
    'hearts-3',
    'hearts-4',
    'hearts-5',
    'hearts-6',
    'hearts-7',
    'hearts-8',
    'hearts-9',
    'hearts-10',
    'hearts-jack',
    'hearts-queen',
    'hearts-king',
    'spades-ace',
    'spades-2',
    'spades-3',
    'spades-4',
    'spades-5',
    'spades-6',
    'spades-7',
    'spades-8',
    'spades-9',
    'spades-10',
    'spades-jack',
    'spades-queen',
    'spades-king'
];
var kingsCup = 0;
var gameComplete = false;

function drawCard() {
    if (gameComplete == false) {
        var randomNumber = Math.floor(Math.random() * (cards.length - 1));
        cards = cards.filter((e, i) => i !== randomNumber);
        console.log(cards.length);
        console.log(cards[randomNumber]);
        document.getElementById("cards").src = 'assets/js/games/cards/' + cards[randomNumber] + '.png';

        switch(cards[randomNumber]) {
            case "clubs-ace":
                document.getElementById("task").innerHTML = "Waterfall!";
            break;
            case "clubs-2":
                document.getElementById("task").innerHTML = "Pick someone to drink."
            break;
            case "clubs-3":
                document.getElementById("task").innerHTML = "Take a drink.";
            break;
            case "clubs-4":
                document.getElementById("task").innerHTML = "Last to touch the floor drinks.";
            break;
            case "clubs-5":
                document.getElementById("task").innerHTML = "All guys drink.";
            break;
            case "clubs-6":
                document.getElementById("task").innerHTML = "All chicks drink.";
            break;
            case "clubs-7":
                document.getElementById("task").innerHTML = "Last to reach for the sky drinks.";
            break;
            case "clubs-8":
                document.getElementById("task").innerHTML = "Pick a mate that will drink anytime you drink.";
            break;
            case "clubs-9":
                document.getElementById("task").innerHTML = "Rhyme";
            break;
            case "clubs-10":
                document.getElementById("task").innerHTML = "Categories";
            break;
            case "clubs-jack":
                document.getElementById("task").innerHTML = "Everyone must drink.";
            break;
            case "clubs-queen":
                document.getElementById("task").innerHTML = "You're now the question master.";
            break;
            case "clubs-king":
                kingsCup = kingsCup + 1;
                if (kingsCup < 4) {
                    document.getElementById("task").innerHTML = "KING! Add a dash of your drink to the kings cup!";
                }
                else {
                    gameComplete = true;
                    document.getElementById("task").innerHTML = "GAME OVER! You must down the kings cup!";
                }
            break;
            case "diamonds-ace":
                document.getElementById("task").innerHTML = "Waterfall!";
            break;
            case "diamonds-2":
                document.getElementById("task").innerHTML = "Pick someone to drink."
            break;
            case "diamonds-3":
                document.getElementById("task").innerHTML = "Take a drink.";
            break;
            case "diamonds-4":
                document.getElementById("task").innerHTML = "Last to touch the floor drinks.";
            break;
            case "diamonds-5":
                document.getElementById("task").innerHTML = "All guys drink.";
            break;
            case "diamonds-6":
                document.getElementById("task").innerHTML = "All chicks drink.";
            break;
            case "diamonds-7":
                document.getElementById("task").innerHTML = "Last to reach for the sky drinks.";
            break;
            case "diamonds-8":
                document.getElementById("task").innerHTML = "Pick a mate that will drink anytime you drink.";
            break;
            case "diamonds-9":
                document.getElementById("task").innerHTML = "Rhyme";
            break;
            case "diamonds-10":
                document.getElementById("task").innerHTML = "Categories";
            break;
            case "diamonds-jack":
                document.getElementById("task").innerHTML = "Everyone must drink.";
            break;
            case "diamonds-queen":
                document.getElementById("task").innerHTML = "You're now the question master.";
            break;
            case "diamonds-king":
                kingsCup = kingsCup + 1;
                if (kingsCup < 4) {
                    document.getElementById("task").innerHTML = "KING! Add a dash of your drink to the kings cup!";
                }
                else {
                    gameComplete = true;
                    document.getElementById("task").innerHTML = "GAME OVER! You must down the kings cup!";
                }
            break;
            case "hearts-ace":
                document.getElementById("task").innerHTML = "Waterfall!";
            break;
            case "hearts-2":
                document.getElementById("task").innerHTML = "Pick someone to drink.";
            break;
            case "hearts-3":
                document.getElementById("task").innerHTML = "Take a drink.";
            break;
            case "hearts-4":
                document.getElementById("task").innerHTML = "Last to touch the floor drinks.";
            break;
            case "hearts-5":
                document.getElementById("task").innerHTML = "All guys drink.";
            break;
            case "hearts-6":
                document.getElementById("task").innerHTML = "All chicks drink.";
            break;
            case "hearts-7":
                document.getElementById("task").innerHTML = "Last to reach for the sky drinks.";
            break;
            case "hearts-8":
                document.getElementById("task").innerHTML = "Pick a mate that will drink anytime you drink.";
            break;
            case "hearts-9":
                document.getElementById("task").innerHTML = "Rhyme";
            break;
            case "hearts-10":
                document.getElementById("task").innerHTML = "Categories";
            break;
            case "hearts-jack":
                document.getElementById("task").innerHTML = "Everyone must drink.";
            break;
            case "hearts-queen":
                document.getElementById("task").innerHTML = "You're now the question master.";
            break;
            case "hearts-king":
                kingsCup = kingsCup + 1;
                if (kingsCup < 4) {
                    document.getElementById("task").innerHTML = "KING! Add a dash of your drink to the kings cup!";
                }
                else {
                    gameComplete = true;
                    document.getElementById("task").innerHTML = "GAME OVER! You must down the kings cup!";
                }
            break;
            case "spades-ace":
                document.getElementById("task").innerHTML = "Waterfall!";
            break;
            case "spades-2":
                document.getElementById("task").innerHTML = "Pick someone to drink.";
            break;
            case "spades-3":
                document.getElementById("task").innerHTML = "Take a drink.";
            break;
            case "spades-4":
                document.getElementById("task").innerHTML = "Last to touch the floor drinks.";
            break;
            case "spades-5":
                document.getElementById("task").innerHTML = "All guys drink.";
            break;
            case "spades-6":
                document.getElementById("task").innerHTML = "All chicks drink.";
            break;
            case "spades-7":
                document.getElementById("task").innerHTML = "Last to reach for the sky drinks.";
            break;
            case "spades-8":
                document.getElementById("task").innerHTML = "Pick a mate that will drink anytime you drink.";
            break;
            case "spades-9":
                document.getElementById("task").innerHTML = "Rhyme";
            break;
            case "spades-10":
                document.getElementById("task").innerHTML = "Categories";
            break;
            case "spades-jack":
                document.getElementById("task").innerHTML = "Everyone must drink.";
            break;
            case "spades-queen":
                document.getElementById("task").innerHTML = "You're now the question master.";
            break;
            case "spades-king":
                kingsCup = kingsCup + 1;
                if (kingsCup < 4) {
                    document.getElementById("task").innerHTML = "KING! Add a dash of your drink to the kings cup!";
                }
                else {
                    gameComplete = true;
                    document.getElementById("task").innerHTML = "GAME OVER! You must down the kings cup!";
                }
            break;
        }
        document.getElementById("kingCount").innerHTML = 4 - kingsCup + " Kings Remaining";
    }

}

I have the game ending when the final king is drawn, but I'd to keep it going without refreshing the page.

[Edit: Full source code added]

Answer 1

At the beginning, lets create a new array under the cards array called currentDeck

var currentDeck = [...cards];

Then in the drawCard() function lets replace the cards array with the currentDeck array we've just created. This will allow us to remove cards from the deck without touching the list of all cards we store as cards .

When the game is over, you can add an else statement where gameComplete would be true which resets the currentDeck array to = the cards array just like we did before.

var currentDeck = [...cards];

cards should never be modified

Answer 2

Here's a solution that uses rando.js 's randoSequence function to simplify the random shuffling. It also uses aternary operator and the javascript pop() method. It'll shuffled the cards and store the shuffled stuff in shuffled . Then it'll remove one at a time from shuffled as it draws cards and refill the shuffled variable with a new shuffled version of the cards values when it runs out.

 var cards = ["a", "b", "c"], shuffled = []; var drawCard = () => (shuffled = shuffled.length? shuffled: randoSequence(cards)).pop().value; //Log the results to show it works... for(var i = 0; i < 10; i++) console.log(drawCard());

 <script src="https://randojs.com/1.0.0.js"></script>