javascript

Figure 6–14. Querying local variables saved to a closure
CHAPTER 6 ■ FUNCTIONS AND ARRAYS
Another way to save default values for bittersweet chocolate, cocoa, and vanilla to a closure would
be to define _bittersweet, _cocoa, and _vanilla parameters for the self-invoking function that returns
the ChocolateChocolate() constructor. Then pass their values to the self-invoking function.
So, as Figure 6–15 displays, saving our default values as named parameters for a closure works just
as well as saving those as local variables for the closure. Note that the definition of ChocolateChocolate()
is the same as in the previous sample. The reason why we did not have to change the definition of
ChocolateChocolate() is that there’s no difference between named parameters and local variables on an
activation object. That is to say, named parameters become local variables. The only difference between
the two is the way you assign a value to them.
var ChocolateChocolate = function (_bittersweet, _cocoa, _vanilla) {
return function (bittersweet, cocoa, vanilla) {
this.bittersweet = [1, "cup", bittersweet || _bittersweet];
this.cocoa = [3, "tbs", cocoa || _cocoa];
this.vanilla = [1, "bean", vanilla || _vanilla];
};
}("Ghirardelli", "Callebaut", "Madagascar Bourbon");
ChocolateChocolate.prototype = {
heavyCream: [1, "cup", "Organic Valley"],
halfHalf: [1, "cup", "Organic Valley"],
sugar: [5/8, "cup"],
yolks: [6]
};
var chocolateChocolate = new ChocolateChocolate("Lindt");
console.dir(chocolateChocolate);
ChocolateChocolate.toString();
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