Ruby on rails 将特定集合/数组项放在rails中的最后一个位置

我在rails中有一个集合/数组，转换为json，如下所示：

@collection = [{"order_number":"123","item":"Paper"},{"order_number":"567","item":"Ruler"},{"order_number":"344","item":"Pen"},{"order_number":"342","item":"Pencil"},{"order_number":"877","item":"Keyboard"}]

@collection = [{"order_number":"123","item":"Paper"},{"order_number":"567","item":"Ruler"},{"order_number":"344","item":"Pen"},{"order_number":"877","item":"Keyboard"},{"order_number":"342","item":"Pencil"}]

@collection.last = @collection[3]

我想挑选订单号为“342”的商品，并将其放在该系列的最后一个位置，因此新系列如下所示：

@collection = [{"order_number":"123","item":"Paper"},{"order_number":"567","item":"Ruler"},{"order_number":"344","item":"Pen"},{"order_number":"342","item":"Pencil"},{"order_number":"877","item":"Keyboard"}]

@collection = [{"order_number":"123","item":"Paper"},{"order_number":"567","item":"Ruler"},{"order_number":"344","item":"Pen"},{"order_number":"877","item":"Keyboard"},{"order_number":"342","item":"Pencil"}]

@collection.last = @collection[3]

理论上，它看起来是这样的：

@collection = [{"order_number":"123","item":"Paper"},{"order_number":"567","item":"Ruler"},{"order_number":"344","item":"Pen"},{"order_number":"342","item":"Pencil"},{"order_number":"877","item":"Keyboard"}]

@collection = [{"order_number":"123","item":"Paper"},{"order_number":"567","item":"Ruler"},{"order_number":"344","item":"Pen"},{"order_number":"877","item":"Keyboard"},{"order_number":"342","item":"Pencil"}]

@collection.last = @collection[3]

但这显然不是花哨的ruby风格，也不会像我的示例中那样对数组进行重新排序。

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此外，我不知道商品的索引，因为它可能会根据用户购物的内容而变化。

如果您有一个商品的索引，它可以归结为

@collection << @collection.delete_at(3)

---

如果你有一个项目的索引，它可以归结为

@collection << @collection.delete_at(3)

---

只需将您的收藏分成两部分（无342订单和有342订单），然后加入它们。应该是这样的：

@collection = @collection.select {|e| e[:order_number] != '342' } + @collection.select {|e| e[:order_number] == '342' }

---

只需将您的收藏分成两部分（无342订单和有342订单），然后加入它们。应该是这样的：

@collection = @collection.select {|e| e[:order_number] != '342' } + @collection.select {|e| e[:order_number] == '342' }

那么：

@collection << @collection.delete_at[@collection.index{|x| x[:order_number] == "342"}]

@collection怎么样：

@collection << @collection.delete_at[@collection.index{|x| x[:order_number] == "342"}]

@collection您也可以尝试以下方法：

> @collection.each_with_index{ |key,value| @collection.push(@collection.delete_at(value)) if key[:order_number] == "344" }
#=>[{:order_number=>"123", :item=>"Paper"}, {:order_number=>"567", :item=>"Ruler"}, {:order_number=>"342", :item=>"Pencil"}, {:order_number=>"877", :item=>"Keyboard"}, {:order_number=>"344", :item=>"Pen"}]

您也可以尝试以下方法：

> @collection.each_with_index{ |key,value| @collection.push(@collection.delete_at(value)) if key[:order_number] == "344" }
#=>[{:order_number=>"123", :item=>"Paper"}, {:order_number=>"567", :item=>"Ruler"}, {:order_number=>"342", :item=>"Pencil"}, {:order_number=>"877", :item=>"Keyboard"}, {:order_number=>"344", :item=>"Pen"}]

您还可以使用以下方法：

您还可以使用以下方法：

你总是知道它是索引吗？或者你需要找到它吗？你想/需要它排序吗？不，我不知道它的索引，我需要找到它。根据客户购买的商品，集合中总是有不同的商品。所以它确实需要排序。你总是知道它是索引吗？或者你需要找到它吗？你想/需要它排序吗？不，我不知道它的索引，我需要找到它。根据客户购买的商品，集合中总是有不同的商品。所以它确实需要排序。对不起，这里不准确，我不知道它的索引。我需要先找到它。然后对数组进行排序。对不起，这里不精确，我不知道它的索引。我需要先找到它。然后对数组进行排序。