29 Dec 08 JavaScript Deck of Cards Pt 2

A co-worker of mine sent me some advice on the JavaScript deck of cards I set up a while back. Everything he said was spot on. Jim, if you're out there, you're insight and advice is always welcome and highly respected. Thanks!

Read your blog.

In the interest of academic feedback (don't take any of this in a negative way), I have a few comments.

It's hard to tell from the current function names, but if the "same_suit" and "same_type" Card methods are meant to be "is_same_..." functions, they you need to change the "=" to "==".
Card = Class.create({
	initialize: function(type,suit) {
		this.type = type;
		this.suit = suit;
	},
	same_suit: function(suit) {
		return this.suit == suit;
	},
	same_type: function(type) {
		return this.type == type;
	},
	toString: function(){
		return this.type + ' of ' + this.suit;
	}
});
JS supports the '+=' operator for strings, so you could change the "message = message + ..." to "message += ..." in the Deck::toString method.

The first time through the Deck::toString function, the modulo check will be true, resulting in message beginning with a '\n' character. Wasn't sure if that is what you wanted.

Here's a minor optimization for the Deck::toString function. It removes the modulo operation from the loop, which is performed 52 times on a full deck, and handles the all of the leading/trailing whitespace (tabs and newlines) automatically:
toString: function() {
	var message = '';
	var i = 0, n = this.cards.length - 2;
	for(; i < n; ) {
		message += this.cards[i++] + '\t\t' + this.cards[i++] + '\n';
	}
	if (i < this.cards.length) {
		message += this.cards[i++];
	}
	if (i < this.cards.length) {
		message += '\t\t' + this.cards[i];
	}
	return message;
}
The following code:
var face_cards = "King,Queen,Jack"
face_cards     = face_cards.split(',');
Could be:
var face_cards = ["King","Queen","Jack"];
I don't think you need the "var i" in the Deck::add_card method.

PS: One other minor update, I got started thinking about UNO and decided to break out the French or Anglo American deck specifications out to a separate class and file.

PPS: Jim caught me using a "=" in place of a "==". These were methods that I hadn't tried yet, but knew that I would need in the future. This is exactly the sort of thing that would have been instantly caught had I written out some tests. I'm a bit late to the game on TDD, but it's something I've been toying with in Ruby and I'm starting to come around. I don't even know where to start unit testing in JavaScript, but I plan on doing a bit of homework on the matter so stay tuned!

Download the code!
JavaScript Deck of Cards V2
Current Version

Tags: cards, javascript, prototype

Filed in Projects, code with 0 Comments

20 Nov 08 JavaScript Deck of Cards

I wrote up a basic model for a 52 card deck of playing cards in JavaScript (using beloved Prototype. I plan on using it to make some very simple card games in the near future. I thought it'd be interesting to post this before I actually used it anywhere so I could take a look at how much it changed after I actually implemented it.

There's not much to see at the moment. You can just shuffle and get a card dump:

<html>
    <head>
        <title>JavaScript Deck of Cards</title>
        <script src="/common/prototype.js" type="text/javascript"></script>
        <script src="deck_of_cards_v1.js" type="text/javascript"></script>
    </head>
    <body>
        <script>
            d = new Deck();
            alert(d);
            d.shuffle();
            alert(d);
        </script>
    </body>
</html>