javascript - 更新 Javascript 对象值给出 null

Question

我正在尝试通过每次有人访问该页面时增加该值来在我的页面上添加“查看”数量。

我有一个像这样的对象:

{
    _id: "55da051afe08e73168fc7aeb",
    url: "https://www.youtube.com/watch?v=eUdM9vrCbow",
    title: "Django Unchained",
    embedUrl: "https://www.youtube.com/embed/eUdM9vrCbow",
    __v: 0,
    downvotes: 0,
    upvotes: 0,
    views: 0,
    created_on: "2015-08-24T13:37:33.951Z",
    desc: "With the help of his mentor, a slave-turned-bounty hunter sets out to rescue his wife from a brutal Mississippi plantation owner."
}

我通过 AngularJS 的“.one()”方法检索该对象:

var movie = Movie.one($routeParams.id);

目标是增加该值。目前我正在这样做:

movie.views++;
movie.put();

但这不起作用，只会给我一个空值，而这确实有效:

movie.views = 10;
movie.put();

我做错了什么？

Answer 1

您无法增加 null 值，默认将其设置为 0(零)。

{
    _id: "55da051afe08e73168fc7aeb",
    url: "https://www.youtube.com/watch?v=eUdM9vrCbow",
    title: "Django Unchained",
    embedUrl: "https://www.youtube.com/embed/eUdM9vrCbow",
    __v: 0,
    downvotes: 0,
    upvotes: 0,
    views: 0, //instead of 'null'
    created_on: "2015-08-24T13:37:33.951Z",
    desc: "With the help of his mentor, a slave-turned-bounty hunter sets out to rescue his wife from a brutal Mississippi plantation owner."
}