Question

我遇到了问题，需要一种简单的方法来对数组进行排序并在视图中使用它

l = Localfeed.select(:id, :locality, :city)

 => #<ActiveRecord::Relation [#<Localfeed id: 94, city: "Cardiff", locality: "Splott">,
 #<Localfeed id: 95, city: "newport", locality: "allt-yr-yn">, #<Localfeed id: 29, city
: "Cardiff", locality: "splott">, #<Localfeed id: 30, city: "Cardiff", locality: "Adams
down">, #<Localfeed id: 31, city: "Cardiff", locality: "Cathays">]>

所以我尝试了类似的东西：

@k = l.group_by {|k| k[:city] }
=> [["newport", [#<Localfeed id: 95, city: "newport", locality: "allt-yr-yn">]], ["Car
diff", [#<Localfeed id: 94, city: "Cardiff", locality: "Splott">, #<Localfeed id: 29, c
ity: "Cardiff", locality: "splott">, #<Localfeed id: 30, city: "Cardiff", locality: "Ad
amsdown">, #<Localfeed id: 31, city: "Cardiff", locality: "Cathays">]]]

在视图中：

          <% @localfeeds.each do |f, t| %>
          <p>city</p>
          <%= f%>
          <p>locality</p>
          <% t.each do |y| %>
          <%= y.locality%>
          <%end%>

我们将不胜感激。

视图中的最终结果应为

City:
link to locality
link to locality
City:
link to locality
link to locality

工作，谢谢

Answer 1

在group_by函数之后，每个哈希值都是Localfeed实例，因此如果要打印每个位置值，请使用：

l = Localfeed.select(:id, :locality, :city)
k = l.group_by {|k| k[:city] }
k.each do |ct, lc|
  puts "#{ct}:"  ## print city
  lc.each {|l| puts "-- #{l.locality}"}  ## print locality in this city group
end

Ruby排序和显示嵌套数组

1 个答案: