检索 json 特定属性？

Question

我正在使用新闻 API 从不同的新闻来源检索与我们不同的新闻。API 调用成功，但HTML无法在循环中检索信息并使用它填充页面。例如，在新闻 API 中，如果我尝试检索新闻的描述并HTML在循环中使用它填充页面，它会给我一个未定义的错误。此代码一次适用于其中一篇文章，但在 for 循环中检索所有文章则无效。 var allArticles =parsedData.articles[0].description;console.log(allArticles);`var request = new XMLHttpRequest;request.open('GET','https://newsapi.org/v2/top-headlines? country=us&apiKey=5060977c4cef473e8e06cb2ad53ea674')request.onload = function(){var response = request.responsevar parsedData = JSON.parse(response)console.log(parsedData)for(var item in parsedData){    //create a title for the news    var allArticles = parsedData.articles[item].description;    console.log(allArticles);    //create the element on html    var titleElement = document.createElement('p');    titleElement.innerHTML = allArticles;    //place it inside the body    document.body.appendChild(titleElement)}}request.onerror = function(){console.log("There appears to be problem accessing the API")}request.send();`控制台显示错误代码：Uncaught TypeError: Cannot read property 'description' of undefined    at XMLHttpRequest.request.onload

Answer 1

for(var item in parsedData.articles)

{

    //create a title for the news

    var allArticles =item.description;

    console.log(allArticles);

    //create the element on html

    var titleElement = document.createElement('p');

    titleElement.innerHTML = allArticles;

    //place it inside the body

    document.body.appendChild(titleElement)

}

Answer 2

进行以下更改，它将起作用：

for(var i;i<=parsedData.length;i++)

{

    //create a title for the news

    var allArticles = parsedData.articles[i].description;

    console.log(allArticles);

    //create the element on html

    var titleElement = document.createElement('p');

    titleElement.innerHTML = allArticles;

    //place it inside the body

    document.body.appendChild(titleElement)

}