underscore _.last

获取最后几个元素

var data = _.last(content, 10);

underscore .map

获得指定的元素

    var data = _.map(
            data, function(blog) {
                return {
                    title: blog.title,
                    slug: blog.slug,
                    description: blog.description,
                    keywords: blog.keywords,
                    created: blog.created
                };
            });

实际应用场景

这里是因为需要获取最后的十个元素到/blog/page/1上，删去其他无用的元素以提高加载速度

    function respages(req, res, next) {
        var data = .last(content, 10);
        data = data.reverse();
        var data = .map(
            data, function(blog) {
                return {
                    title: blog.title,
                    slug: blog.slug,
                    description: blog.description,
                    keywords: blog.keywords,
                    created: blog.created
                };
            });
        res.json(data, {
            'content-type': 'application/json; charset=utf-8'
        });
    }

undercore _.where

遍历list中的每一个值，返回一个数组，这个数组包含包含properties所列出的属性的所有的键 - 值对。

这里用于url匹配

    function resslug(req, res, next) {
        var data = _.where(content, {
            slug: req.params.slug
        });
        res.json(data, {
            'content-type': 'application/json; charset=utf-8'
        });
    }