# Collection类 ### 介绍 `October\Rain\Support\Collection`类提供一个流畅，方便的包装用于与数据的数组工作。例如，查看以下代码。我们将从数组创建一个新的集合实例，`strtoupper`在每个元素上运行该函数，然后删除所有空元素： ~~~ $collection = new October\Rain\Support\Collection(['stewie', 'brian', null]); $collection = $collection ->map(function ($name) { return strtoupper($name); }) ->reject(function ($name) { return empty($name); }) ; ~~~ 在`Collection`类允许您链中的方法来执行流利映射和底层数组的减少。通常，每个`Collection`方法都返回一个全新的`Collection`实例。 ### [](https://octobercms.com/docs/services/collections#creating-collections)创建收藏 如上所述，将数组传递给`October\Rain\Support\Collection`类的构造函数将为给定数组返回一个新实例。因此，创建集合非常简单： ~~~ $collection = new October\Rain\Support\Collection([1, 2, 3]); ~~~ 默认情况下，[数据库模型的](https://octobercms.com/docs/database/model)集合始终作为`Collection`实例返回；但是，请`Collection`在适合您的应用程序的任何地方随意使用该类。 ### 高阶消息 集合还支持“高级消息”，这是对集合执行常见操作的捷径。提供更高阶的信息收集方法有：[`average`](https://octobercms.com/docs/services/collections#method-average)，[`avg`](https://octobercms.com/docs/services/collections#method-avg)，[`contains`](https://octobercms.com/docs/services/collections#method-contains)，[`each`](https://octobercms.com/docs/services/collections#method-each)，[`every`](https://octobercms.com/docs/services/collections#method-every)，[`filter`](https://octobercms.com/docs/services/collections#method-filter)，[`first`](https://octobercms.com/docs/services/collections#method-first)，[`flatMap`](https://octobercms.com/docs/services/collections#method-flatmap)，[`groupBy`](https://octobercms.com/docs/services/collections#method-groupby)，[`keyBy`](https://octobercms.com/docs/services/collections#method-keyby)，[`map`](https://octobercms.com/docs/services/collections#method-map)，[`max`](https://octobercms.com/docs/services/collections#method-max)，[`min`](https://octobercms.com/docs/services/collections#method-min)，[`partition`](https://octobercms.com/docs/services/collections#method-partition)，[`reject`](https://octobercms.com/docs/services/collections#method-reject)，[`some`](https://octobercms.com/docs/services/collections#method-some)，[`sortBy`](https://octobercms.com/docs/services/collections#method-sortby)，[`sortByDesc`](https://octobercms.com/docs/services/collections#method-sortbydesc)，[`sum`](https://octobercms.com/docs/services/collections#method-sum)，和[`unique`](https://octobercms.com/docs/services/collections#method-unique)。 每个高阶消息都可以作为集合实例上的动态属性来访问。例如，让我们使用`each`高阶消息在集合内的每个对象上调用一个方法： ~~~ $users = User::where('votes', '>', 500)->get(); $users->each->markAsVip(); ~~~ 同样，我们可以使用`sum`较高顺序的消息来收集用户集合的“票数”总数： ~~~ $users = User::where('group', 'Development')->get(); return $users->sum->votes; ~~~