Question

我想抓取https://api.coindesk.com/v1/bpi/currentprice/BTC.json/并收取比特币的价格，将其保存到变量中。到目前为止，这是我的js / jQuery代码

$.getJSON('http://www.whateverorigin.org/get?url=' + encodeURIComponent('https://api.coindesk.com/v1/bpi/currentprice/BTC.json/') + '&callback=?', function(data){
    console.log(data.contents);
    var za = $((data.contents).find("rate_float").text();
    alert(za)
}));

我一直收到错误：

参数列表后面的
Uncaught SyntaxError：missing）它指向一行：

var za = $((data.contents).find("rate_float").text();

不知道出了什么问题。我一遍又一遍地检查过但是所有的括号都关闭了。任何帮助赞赏。感谢

Answer 1

返回的值是JSON字符串。您需要解析才能将该字符串转换为js对象，如：

{
     "time": {
         "updated": "Mar 28, 2018 16:58:00 UTC",
         "updatedISO": "2018-03-28T16:58:00+00:00",
         "updateduk": "Mar 28, 2018 at 17:58 BST"
     },
     "disclaimer": "This data was produced from the CoinDesk Bitcoin Price Index (USD). Non-USD currency data converted using hourly conversion rate from openexchangerates.org",
     "bpi": {
         "USD": {
             "code": "USD",
             "rate": "7,882.7938",
             "description": "United States Dollar",
             "rate_float": 7882.7938
         },
         "BTC": {
             "code": "BTC",
             "rate": "1.0000",
             "description": "Bitcoin",
             "rate_float": 1
         }
     }
 }

为了获得USD rate_float，你可以写：

var za = JSON.parse(data.contents).bpi.USD.rate_float;

完整代码：

$.getJSON('http://www.whateverorigin.org/get?url=' +
        encodeURIComponent('https://api.coindesk.com/v1/bpi/currentprice/BTC.json') + '&callback=?', function (data) {
    console.log(data.contents);
    var za = JSON.parse(data.contents).bpi.USD.rate_float;
    alert(za)
});

Answer 2

工作演示

＆＃13;

// handles the click event, sends the query
function getSuccessOutput() {
    $.ajax({
        url:'https://api.coindesk.com/v1/bpi/currentprice/BTC.json',
        complete: function (response) {
            $('#output').html(JSON.parse(response.responseText).bpi.USD.rate_float);
        },
        error: function () {
            $('#output').html('there was an error!');
        },
    });
    return false;
}

＆＃13;

<script src="https://ajax.googleapis.com/ajax/libs/jquery/2.1.1/jquery.min.js"></script>
<a href="#" onclick="return getSuccessOutput();"> Get USD price </a>
<hr>
<div id="output">Click on link to get the output</div>

＆＃13;

如何使用JavaScript抓取JSON页面并收集数据

2 个答案: