無法從NodeJS中的JSON響應中獲取值

Question

我正在嘗試檢查從查詢返回的值。這個結果是JSON格式。我的代碼工作，直到我的條件聲明。
在調試過程中，我發現我的條件語句總是失敗，因爲我試圖從JSON檢索並比較的值始終未定義。

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])) 

被返回的身體看起來是這樣的：

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

當我調試，我看到以下內容：

JSON Values

然而，解析值顯示爲：

Parsed values

任何幫助，非常感謝。謝謝，

Answer 1

你正在接收的是一個對象數組而不是對象對象，因此你應該首先使用索引訪問它們，然後訪問屬性。 假設JSON響應的格式總是相同的，這裏是工作的JSfiddle鏈接，下面是來自How to get index of object by its property in javascript的文章answer的啓發的示例代碼。

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");