JavaScript recursive array iterator

Array.prototype.recursiveArrayIterator.js

/**
 * Prototype for recursively iterating over an array of
 * arrays.
 * @author Dave Mackintosh
 * @param callback function
 */
Array.prototype.recursiveArrayIterator = function (cb) {
	this.forEach(function (obj, inx) {
		// If it's an array we want to fire another iterator
		// with our parent array as a separate argument
		if (obj.constructor === Array) {
			obj.recursiveArrayIterator.call(obj, cb);
		} else {
			// If it isn't an array, fire the callback 
			// with helpful arguments
			cb.apply(this, [obj, inx]);
		}
	});
};