javascript - AJAX:如何读取 JSON 数据

Question

我正在尝试从 url 获取 json 数据。这是js

var myRequest = new XMLHttpRequest();
  myRequest.open('GET', 'URL that has JSON format');
  myRequest.onload = function() {
    var myData = JSON.parse(myRequest.responseText);
    console.log(myData);
  };
myRequest.send();

JSON数据格式是这样的

"ING":
    [
        {
            "#":1,
            "Team":"Manchester City",
            "Main":37,
            "Poin":97
        },
        {
            "#":2,
            "Team":"Manchester United",
            "Main":37,
            "Poin":78
        },
        {
            "#":3,
            "Team":"Tottenham Hotspur",
            "Main":37,
            "Poin":74
        },
        {
            "#":4,
            "Team":"Liverpool",
            "Main":37,
            "Poin":72
        },
        {
            "#":5,
            "Team":"Chelsea",
            "Main":37,
            "Poin":70
        }
    ]
}

例如我想获取 Chealsea。我怎样才能做到这一点？我知道我必须改变

console.log(myData);

我该怎么办？谢谢

Answer 1

您可以使用回调、promise 或 async/await。您可以通过以下方式使用回调来获取和使用检索到的数据:

function getUrl(url, callback) {
  var myRequest = new XMLHttpRequest();
  myRequest.open('GET', url);
  myRequest.onload = function() {
    var myData = JSON.parse(myRequest.responseText);
    console.log(myData);
    callback(myData);
  };
  myRequest.send();
}

您请求并使用您的数据，如下所示:

getUrl('URL for JSON DATA', function(data) {
  // find chealsea
  var chealsea = data.ING.find(function(entry) { return entry.Team === 'Chealsea' });
  console.log(chealsea);
});