# Collection類 ### 介紹 `October\Rain\Support\Collection`類提供一個流暢，方便的包裝用于與數據的數組工作。例如，查看以下代碼。我們將從數組創建一個新的集合實例，`strtoupper`在每個元素上運行該函數，然后刪除所有空元素： ~~~ $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`類允許您鏈中的方法來執行流利映射和底層數組的減少。通常，每個`Collection`方法都返回一個全新的`Collection`實例。 ### [](https://octobercms.com/docs/services/collections#creating-collections)創建收藏 如上所述，將數組傳遞給`October\Rain\Support\Collection`類的構造函數將為給定數組返回一個新實例。因此，創建集合非常簡單： ~~~ $collection = new October\Rain\Support\Collection([1, 2, 3]); ~~~ 默認情況下，[數據庫模型的](https://octobercms.com/docs/database/model)集合始終作為`Collection`實例返回；但是，請`Collection`在適合您的應用程序的任何地方隨意使用該類。 ### 高階消息 集合還支持“高級消息”，這是對集合執行常見操作的捷徑。提供更高階的信息收集方法有：[`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)。 每個高階消息都可以作為集合實例上的動態屬性來訪問。例如，讓我們使用`each`高階消息在集合內的每個對象上調用一個方法： ~~~ $users = User::where('votes', '>', 500)->get(); $users->each->markAsVip(); ~~~ 同樣，我們可以使用`sum`較高順序的消息來收集用戶集合的“票數”總數： ~~~ $users = User::where('group', 'Development')->get(); return $users->sum->votes; ~~~