刮擦JSON网页JavaScript时出错

Question

我正在尝试刮擦JSON网页，但它无法正常工作。不知道怎么了。这是我的JS/jQuery代码：

 $.getJSON('http://www.whateverorigin.org/get?url=' + encodeURIComponent('https://api.coinmarketcap.com/v1/ticker/ethereum/') + '&callback=?', function (data) {
    console.log(data.contents);
    var ethPrice = JSON.parse(data.contents).price_usd;
    alert(ethPrice)
});

我得到错误：

Uncaught SyntaxError: Unexpected token o in JSON at position 1
    at JSON.parse (<anonymous>)
    at Object.success (scripts.js:6)
    at i (jquery.min.js:2)
    at Object.fireWith [as resolveWith] (jquery.min.js:2)
    at A (jquery.min.js:4)
    at HTMLScriptElement.c (jquery.min.js:4)
    at HTMLScriptElement.dispatch (jquery.min.js:3)
    at HTMLScriptElement.q.handle (jquery.min.js:3)

请帮忙。非常感谢：(

Answer 1

看起来您的JSON结果是数组JSON。因此，由于它是数组，因此无法访问字段。可能，您需要这个。

$.getJSON('http://www.whateverorigin.org/get?url=' + encodeURIComponent('https://api.coinmarketcap.com/v1/ticker/ethereum/') + '&callback=?', function (data) {
    console.log(data.contents);
    var response = JSON.parse(data.contents);
    for (var i = 0; i < response.length; i ++) {
        var ethPrice = response[i].price_usd;
        alert(ethPrice);
    }
});

Answer 2

You might also need to confirm if data has contents.
$.getJSON('http://www.whateverorigin.org/get?url=' + 
encodeURIComponent('https://api.coinmarketcap.com/v1/ticker/ethereum/') 
+ '&callback=?', function (data) {
if (data && data.contents) {
    console.log(data.contents);
 var contents = JSON.parse(data.contents);
//loop through contents for a price_usd attribute
for (let i = 0; i < contents.length; i++) {
if (contents[i].price_usd) {
alert(contents[i].price_usd)
}
}

} }(;