Loop Timer Testing

var photos = [], captions = [];
for (var i = 0, len = library.length; i < len; i++) {
    photos.push(library[i]["img"]);
    captions.push(library[i]["caption"]);
}

var photos = [], captions = [], len = library.length;
for (var i = len; i--;) {
    var o = library[i];
    photos[i] = o.img;
    captions[i] = o.caption;
}