从JSON Ruby on Rails中获取第一个数组值

Question

我有这个JSON从uri调用返回

[
  "cat",
  [
    "cat",
    "cat tree",
    "cat toys",
    "cat bed",
    "cat litter",
    "cat ears",
    "cat food",
    "catastrophe",
    "caterpillar",
    "catan"
  ],
  [
    {
      "nodes": [
        {"name": "Pet Supplies", "alias": "pets"},
        {"name": "Home & Kitchen", "alias": "garden"},
        {"name": "Women's Clothing", "alias": "fashion-womens-clothing"},
        {"name": "Toys & Games", "alias": "toys-and-games"}
      ]
    },
    {}, {}, {}, {}, {}, {}, {}, {}, {}
  ],
  []
]

我试图在ruby on rails中获得第一个"猫"(以斜体显示)之后的数组。我试着

a= JSON.parse(doc) 
result = a["cat"]

不起作用。我得到一个奇怪的整数错误

Answer 1

> doc = "..." # the json string
> json = JSON.parse(doc)
> result = json.detect{|e| e.is_a?(Array)}

result现在:

=> ["cat", "cat tree", "cat toys", "cat bed", "cat litter", "cat ears", "cat food", "catastrophe", "caterpillar", "catan"]

Answer 2

你只需要:

json = JSON.parse(doc) 
result = json[1]

数据结构是一个数组。索引0处的元素是字符串"cat"。索引1处的元素为数组[ "cat", "cat trees", "cat toys", ... ]。