无法从 NodeJS 中的 JSON 响应中获取值

Question

我正在尝试检查从查询返回的值。此结果为 JSON 格式。我的代码工作，直到我的条件语句。
在调试时我发现我的条件语句总是失败，因为我试图从 JSON 检索和比较的值总是未定义。

var promise = insertDataInMongo([body, token]);
var newBody = JSON.parse(body);

if (newBody.paging.facebookPost !== -1 || newBody.paging.youtube !== -1 || newBody.paging.twitter !== -1 || newBody.paging.facebook !== -1 || newBody.paging.reddit !== -1 || newBody.paging.youtubeComment !== -1 || newBody.paging.news !== -1)
    promise.then(getAthleteMedia([athlete, token, newBody.paging.facebook, newBody.paging.facebookPost, newBody.paging.reddit, newBody.paging.youtube, newBody.paging.youtubeComment, newBody.paging.twitter, newBody.paging.news]))

返回的正文如下所示：

{ "paging": [
{
  "youtubeComment": -1
},
{
  "youtube": -1
},
{
  "twitter": -1
},
{
  "facebook": -1
},
{
  "reddit": -1
},
{
  "facebookPost": -1
},
{
  "news": -1
}
]}

调试时，我看到以下内容：

JSON Values

但是，解析值显示为：

Parsed values

非常感谢任何帮助。谢谢，

Answer 1

您收到的是对象数组而不是对象的对象，因此您应该先使用索引然后使用属性访问它们。 假设 JSON 响应的格式始终相同，这里是有效的JSfiddle 链接，下面是受How to get index of object by its property in javascript 帖子的answer 启发的示例代码。

var newBody = {
  "paging": [{
    "youtubeComment": -1
  }, {
    "youtube": -1
  }, {
    "twitter": -1
  }, {
    "facebook": -1
  }, {
    "reddit": -1
  }, {
    "facebookPost": -1
  }, {
    "news": -1
  }]
};


function check(array, attr, value) {
  for (var i = 0; i < array.length; i += 1) {
    if (array[i][attr] === value) {
      return false;
    }
  }
  return true;
}

function get_value(array, attr) {
  for (var i = 0; i < array.length; i += 1) {
    if (array[i].hasOwnProperty(attr)) {
      return array[i][attr];
    }
  }
}

if (check(newBody.paging, "facebook", -1) || check(newBody.paging, "youtubeComment", -1) || check(newBody.paging, "youtube", -1) || check(newBody.paging, "twitter", -1) || check(newBody.paging, "reddit", -1) || check(newBody.paging, "facebookPost", -1) || check(newBody.paging, "news", -1)) {
  // promise.then(getAthleteMedia([athlete, token, get_value(newBody.paging, "facebook"), ... get_value(newBody.paging, "news")]));
  // similarly just pass the function in your promise, hope it clears how to get the values as well
  console.log(get_value(newBody.paging, "facebook"));

} else console.log("not in if");