给定一个json对象，如何遍历rails中的对象答案

【问题标题】：given a json object, how to iterate through the object in rails给定一个json对象，如何遍历rails中的对象
【发布时间】：2011-10-19 15:18:13
【问题描述】：

我的应用正在将以下 json 对象发布到 rails。

[{\"completed\":false,\"id\":196,\"position\":0,\"title\":\"Item 1\",\"updated_at\":\"2011-08-03T21:17:09Z\"},{\"completed\":false,\"id\":193,\"position\":1,\"title\":\"Item X\",\"updated_at\":\"2011-08-03T21:16:19Z\"},{\"completed\":false,\"id\":197,\"position\":2,\"title\":\"Item 2\",\"updated_at\":\"2011-08-03T21:17:11Z\"},{\"completed\":false,\"id\":192,\"position\":3,\"title\":\"Item Z\",\"updated_at\":\"2011-08-03T21:16:17Z\"},{\"completed\":false,\"id\":194,\"position\":4,\"title\":\"Item Y\",\"updated_at\":\"2011-08-03T21:16:21Z\"},{\"completed\":false,\"id\":195,\"position\":5,\"title\":\"Item P\",\"updated_at\":\"2011-08-03T21:16:25Z\"},{\"completed\":false,\"id\":199,\"position\":6,\"title\":\"Why you no stay done?\",\"updated_at\":\"2011-08-03T23:22:41Z\"},{\"completed\":false,\"id\":200,\"position\":7,\"title\":\"Wow\",\"updated_at\":\"2011-08-04T00:02:07Z\"},{\"completed\":false,\"id\":201,\"position\":8,\"title\":\"Hello World\",\"updated_at\":\"2011-08-04T00:02:11Z\"},{\"completed\":false,\"id\":202,\"position\":9,\"title\":\"GOLDEN GATE BRIDGE CATALYST,\",\"updated_at\":\"2011-08-04T00:44:19Z\"}]

我无法遍历该对象。我能做到：

JSON.parse(list_items_open).each do |item|
  Rails.logger.info item.inspect
end

哪个输出：

{"completed"=>false, "id"=>193, "position"=>0, "title"=>"Item X", "updated_at"=>"2011-08-03T21:16:19Z"}
{"completed"=>false, "id"=>197, "position"=>1, "title"=>"Item 2", "updated_at"=>"2011-08-03T21:17:11Z"}
{"completed"=>false, "id"=>192, "position"=>2, "title"=>"Item Z", "updated_at"=>"2011-08-03T21:16:17Z"}
{"completed"=>false, "id"=>196, "position"=>3, "title"=>"Item 1", "updated_at"=>"2011-08-03T21:17:09Z"}
{"completed"=>false, "id"=>194, "position"=>4, "title"=>"Item Y", "updated_at"=>"2011-08-03T21:16:21Z"}
{"completed"=>false, "id"=>195, "position"=>5, "title"=>"Item P", "updated_at"=>"2011-08-03T21:16:25Z"}
{"completed"=>false, "id"=>199, "position"=>6, "title"=>"Why you no stay done?", "updated_at"=>"2011-08-03T23:22:41Z"}
{"completed"=>false, "id"=>200, "position"=>7, "title"=>"Wow", "updated_at"=>"2011-08-04T00:02:07Z"}
{"completed"=>false, "id"=>201, "position"=>8, "title"=>"Hello World", "updated_at"=>"2011-08-04T00:02:11Z"}
{"completed"=>false, "id"=>202, "position"=>9, "title"=>"GOLDEN GATE BRIDGE CATALYST,", "updated_at"=>"2011-08-04T00:44:19Z"}

但我无法获得实际的 id：

JSON.parse(list_items_open).each do |item|
  Rails.logger.info item[:id]
end

那什么也不返回。关于如何获取项目 ID 的建议？

谢谢

【问题讨论】：

标签： ruby-on-rails ruby json ruby-on-rails-3

【解决方案1】：

符号和字符串是不同的东西（除非您使用HashWithIndifferentAccess），您应该使用字符串作为键：

JSON.parse(list_items_open).each do |item|
  Rails.logger.info item['id']
end

这是一个带有 'id' 键的哈希：

{ "id" => 193 }

这是一个带有 :id 键的哈希：

{ :id => 193 }

【讨论】：