Codecademy Blackjack Final Challenge

gistfile1.js

/**
 * This is an example of a working Black Jack game.
 * This was my entry for the Blackjack Final Challenge at
 * http://www.codecademy.com/courses/blackjack-part-3
 */

// Card Constructor
var game_deck;
var Card = function (suit, number) {
    var card_suit = suit;
    var card_number = number;
    
    this.getSuit = function () { return card_suit; };
    this.getNumber = function () { return card_number; };
    this.getValueStr = function () {
        switch (card_number) {
            case 1: return "Ace";
            case 11: return "Jack";
            case 12: return "Queen";
            case 13: return "King";
            default: return "" + card_number;
        }
    };
    this.getSuitStr = function () {
        switch (card_suit) {
            case 1: return "diamonds";
            case 2: return "hearts";
            case 3: return "spades";
            case 4: return "clubs";
            default: return "[unknown suit value: "+ card_suit +"]";
        }
    };

    // Get the card's score value.
    // 1 (Ace) : 1 or 11
    // 2 - 10 : card value
    // 11,12,13 (face cards) : 10
    this.getValue = function () {
        if (card_number === 1) { return 11; } // Ace
        else if (card_number >= 10) { return 10; } // Face card
        else { return card_number; }
    };
};

var Deck = function () {
    var full_deck = [];
    // Create deck programatically (saves typing, should be hard coded)
    for (var i = 1; i <= 52; i++) { full_deck.push(i); }
    
    // shuffle deck
    // Shuffle algorithm described here:
    // http://en.wikipedia.org/wiki/Fisher-Yates_shuffle
    this.shuffle = function () {
        var i,j,x;
        // Iterate over array in reverse
        for (i = full_deck.length -1; i > 0; i--) {
            // Only select random position based on what is left.
            j = Math.floor(Math.random()*i);
            // Exchange a[j] with a[i]
            x = full_deck[i];
            full_deck[i] = full_deck[j];
            full_deck[j] = x;
        }
    };
    
    this.getNewCard = function() {
        var card_num = full_deck.pop();
        var val = card_num % 13 + 1;
        var suit = Math.ceil(card_num / 13);
        return new Card(suit, val);
    };
};

function deal() { return game_deck.getNewCard(); }

var Hand = function () {
    var my_hand = [];

    // Adds two cards top the hand
    my_hand.push(deal());
    my_hand.push(deal());

    this.getHand = function () {
        return my_hand;
    };
    
    this.score = function () {
        var i,x;
        var sum = 0;
        var aces = 0;
        for (i = 0; i < my_hand.length; i++) {
            x = my_hand[i].getValue();
            if (x === 11) {
                aces++;
                sum++; // Lowest value of an ace
            }
            else { sum += x; }
        }
        while (sum < 21 && aces > 0) {
            // Calulate based on 10 since a 1 was already
            // added above as a minimum for an ace.
            if (sum + 10 <= 21) {
                sum += 10;
                aces--;
            }
            else { break; }
        }
        return sum;
    };
    
    this.printHand = function () {
        var output = [];
        for (var i = 0; i < my_hand.length; i++) {
            output.push(my_hand[i].getValueStr() +" of "+ my_hand[i].getSuitStr());
        }
        return output.join(", ");
    };
    
    this.hitMe = function () { my_hand.push(deal()); };
    
    this.busted = function () { return (this.score() > 21); };
};

function playAsDealer() {
    var dealer_hand = new Hand();
    while (dealer_hand.score() < 17) { dealer_hand.hitMe(); }
    return dealer_hand;
}

function playAsUser() {
    var player_hand = new Hand();
    var continue_loop = true;
    while ( continue_loop && !player_hand.busted() )
    {
        continue_loop = confirm(
            "You have: " + player_hand.printHand() +
            "\nScore: " + player_hand.score() +
            "\n\nWould you like another card?"
        );
        if (continue_loop) { player_hand.hitMe(); }
    }
    return player_hand;
}

function declareWinner(userHand,dealerHand) {
    var s = {
        win: "You win!",
        lose: "You lose!",
        tie: "You tied!"
    };
    var dscore = dealerHand.score();
    var pscore = userHand.score();
    if (pscore > 21) {
        if (dscore > 21) { return s.tie; }
        else { return s.lose; }
    }
    else if (dscore > 21) { return s.win; }
    else if (pscore > dscore) { return s.win; }
    else if (pscore < dscore) { return s.lose; }
    else { return s.tie; }
}

function playGame() {
    game_deck = new Deck();    
    // Shuffle the deck
    game_deck.shuffle();

    var player = playAsUser();
    var dealer = playAsDealer();

    var winner = "";
    var pprompt = (player.busted()) ? "You busted! Score" : "Your score";
    var dprompt = (dealer.busted()) ? "Dealer busted! Score" : "Dealer's score";

    winner += "\n"+ pprompt +": "+ player.score();
    winner += " ("+ player.printHand() +")\n";
    winner += dprompt +": "+ dealer.score();
    winner += " ("+ dealer.printHand() +")\n";
    winner += "\n"+ declareWinner(player, dealer);

    console.log(winner);
}

playGame();