javascript

CHAPTER 6 ■ FUNCTIONS AND ARRAYS
freshLemonJuice: [2, "tsp"],
toString: function () { return "[object WildMaineBlueberry]";}
};
var wildMaineBlueberry = new WildMaineBlueberry("Dole frozen wild blueberries", "Tahitian");
wildMaineBlueberry.toString();
// "[object WildMaineBlueberry]"
Figure 6–6. WildMaineBlueberry.prototype.toString() overrides Object.prototype.toString().
Native JavaScript constructors defined by ECMAScript or DOM always override
Object.prototype.toString(). For example, if we call toString() on the array in
wildMaineBlueberry.heavyCream, JavaScript glues the elements together with commas instead of
returning "[object Array]", which is what Object.prototype.toString() returns for an array when it is
not overridden. Similarly, if we call toString() on the constructor function WildMaineBlueberry,
JavaScript return its definition as a string. Try doing both, verifying your work with Figure 6–7.
var WildMaineBlueberry = function(blueberries, vanilla) {
this.blueberries = [2, "cup", blueberries ? blueberries : "fresh wild Maine blueberries"];
this.vanilla = [1, "bean", vanilla ? vanilla : "Madagascar Bourbon"];
};
WildMaineBlueberry.prototype = {
heavyCream: [1, "cup", "Organic Valley"],
halfHalf: [1, "cup", "Organic Valley"],
sugar: [5/8, "cup"],
yolks: [6],
freshLemonJuice: [2, "tsp"],
toString: function () { return "[object WildMaineBlueberry]";}
};
var wildMaineBlueberry = new WildMaineBlueberry("Dole frozen wild blueberries", "Tahitian");
wildMaineBlueberry.heavyCream.toString();
// "1,cup,Organic Valley"
WildMaineBlueberry.toString();
// "function (blueberries, vanilla) { this.blueberries = [2, "cup", blueberries ? blueberries
: "fresh wild Maine blueberries"]; this.vanilla = [1, "bean", vanilla ? vanilla : "Madagascar
Bourbon"]; }"
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