Question

我有一个很大的数组：

[
{id: 1, name: 'abs', surname: 'abs'},
{id: 1, name: 'abs', surname: 'abs'},
...
{id: 1, name: 'abs', surname: 'abs'},
]

我需要添加新的＆＃39;组＆＃39;密钥到每个哈希。前五个哈希应该有＆＃39;组：＆＃39;：1，后五个哈希应该有＆＃39;组＆＃39;：2例如进入结果数组：

[
{id: 1, name: 'abs', surname: 'abs', group: 1},
{id: 1, name: 'abs', surname: 'abs', group: 1},
{id: 1, name: 'abs', surname: 'abs', group: 1},
{id: 1, name: 'abs', surname: 'abs', group: 1},
{id: 1, name: 'abs', surname: 'abs', group: 1},
{id: 1, name: 'abs', surname: 'abs', group: 2},
...
{id: 1, name: 'abs', surname: 'abs', group: N},
]

如果我使用Array＃group_by和Array＃each_with_index方法代码工作缓慢，导致数组有很多记录...我怎么能用ruby来让代码运行得更快？

Answer 1

我减少了您的输入样本，因为不需要那么大的样本。您可以通过此代码插入如何执行所需操作：

require 'json'

foo = [
  {id: 1, name: 'abs', surname: 'abs'},
  {id: 1, name: 'abs', surname: 'abs'},
  {id: 1, name: 'abs', surname: 'abs'},
  {id: 1, name: 'abs', surname: 'abs'},
]

foo.each_slice(2).with_index(1){ |a, i| a.each{ |h| h[:group] = i } }
puts foo.to_json
# >> [{"id":1,"name":"abs","surname":"abs","group":1},{"id":1,"name":"abs","surname":"abs","group":1},{"id":1,"name":"abs","surname":"abs","group":2},{"id":1,"name":"abs","surname":"abs","group":2}]

以下是看起来更具可读性的内容：

puts JSON::pretty_generate(foo)
# >> [
# >>   {
# >>     "id": 1,
# >>     "name": "abs",
# >>     "surname": "abs",
# >>     "group": 1
# >>   },
# >>   {
# >>     "id": 1,
# >>     "name": "abs",
# >>     "surname": "abs",
# >>     "group": 1
# >>   },
# >>   {
# >>     "id": 1,
# >>     "name": "abs",
# >>     "surname": "abs",
# >>     "group": 2
# >>   },
# >>   {
# >>     "id": 1,
# >>     "name": "abs",
# >>     "surname": "abs",
# >>     "group": 2
# >>   }
# >> ]

以下是发生的事情：

each_slice将数组切成N个大小的块。

pp foo.each_slice(2).to_a
# >> [[{:id=>1, :name=>"abs", :surname=>"abs", :group=>1},
# >>   {:id=>1, :name=>"abs", :surname=>"abs", :group=>1}],
# >>  [{:id=>1, :name=>"abs", :surname=>"abs", :group=>2},
# >>   {:id=>1, :name=>"abs", :surname=>"abs", :group=>2}]]

with_index将增量值添加到传递给块的参数列表中。这被分配给块中的i。

pp foo.each_slice(2).with_index(1).to_a
# >> [[[{:id=>1, :name=>"abs", :surname=>"abs", :group=>1},
# >>    {:id=>1, :name=>"abs", :surname=>"abs", :group=>1}],
# >>   1],
# >>  [[{:id=>1, :name=>"abs", :surname=>"abs", :group=>2},
# >>    {:id=>1, :name=>"abs", :surname=>"abs", :group=>2}],
# >>   2]]

Answer 2

怎么样：

foo = [
  {id: 1, name: 'abs', surname: 'abs'},
  {id: 1, name: 'abs', surname: 'abs'},
  {id: 1, name: 'abs', surname: 'abs'},
  {id: 1, name: 'abs', surname: 'abs'},
]
group_count =5

foo.each_with_index do |u,i|
  u['highlight_group'] = i.div( group_count ) 
end

puts foo

如何将新密钥添加到json哈希数组中？

2 个答案: