javascript

Figure 6–18. Moving the () operator outside the parentheses works fine, too.
Passing a Configuration Object
CHAPTER 6 ■ FUNCTIONS AND ARRAYS
Often, if you have a number of optional parameters, such as in our closure samples, you will want to
pass a configuration object rather than separate parameters. Doing so prevents your having to pass "" or
some other falsy value parameters prior to the one you want to explicitly pass as in the following sample:
var ChocolateChocolate = function () {
var _bittersweet = "Ghirardelli",
_cocoa = "Callebaut",
_vanilla = "Madagascar Bourbon";
return function (bittersweet, cocoa, vanilla) {
this.bittersweet = [1, "cup", bittersweet || _bittersweet];
this.cocoa = [3, "tbs", cocoa || _cocoa];
this.vanilla = [1, "bean", vanilla || _vanilla];
};
}();
ChocolateChocolate.prototype = {
heavyCream: [1, "cup", "Organic Valley"],
halfHalf: [1, "cup", "Organic Valley"],
sugar: [5/8, "cup"],
yolks: [6]
};
var chocolateChocolate = new ChocolateChocolate("", "", "Tahitian");
console.dir(chocolateChocolate);
So here’s how we can remedy that bugaboo by defining one parameter named pref. As Figure 6–19
displays, this prevents our having to pass empty strings for bittersweet and cocoa in order to pass
“Tahitian” for vanilla.
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