javascript

CHAPTER 6 ■ FUNCTIONS AND ARRAYS
206
toString: function () { return "[object WildMaineBlueberry]";}
};
var wildMaineBlueberry = new WildMaineBlueberry("Dole frozen wild blueberries", "Tahitian");
Array.isArray(wildMaineBlueberry.halfHalf);
// true
Array.isArray(wildMaineBlueberry.halfHalf[2]);
// false
Figure 6–9. Verifying arrayness with the native Array.isArray() method or our knock-off
Rewriting cloneMembers()
Now that we have a better way to verify arrayness than simply groking whether a method like pop() or
slice() is defined, let’s rework cloneMembers() accordingly. Then try churning a quart of Coffee Heath
Bar Crunch by cloning and augmenting a quart of Vanilla Heath Bar Crunch, verifying your work with
Figure 6–10:
if (Array.isArray === undefined) {
Array.isArray = function(v) {
return {}.toString.apply(v) === "[object Array]";
};
}
var cloneMembers = function (donor, donee) {
donee = donee || {};
for (var m in donor) {
if (donor.hasOwnProperty(m)) {
if (typeof donor[m] === "object" && donor[m] !== null) {
donee[m] = Array.isArray(donor[m]) ? [] : {};
cloneMembers(donor[m], donee[m]);
} else {