从 JSON 数组中提取并显示一个值答案

【问题标题】：Extract and Display a Value from a JSON Array从 JSON 数组中提取并显示一个值
【发布时间】：2016-01-25 13:55:09
【问题描述】：

我正在使用 Coindesk JSON API 获取最新的比特币汇率。

http://api.coindesk.com/v1/bpi/currentprice/GBP.json

我想在我的网站页面上以纯文本形式显示汇率，例如：“284.0493”。从 JSON 数组中提取正确值并将其显示在 HTML div 中的正确方法是什么？

任何使用 JavaScript、PHP 甚至 Python 的解决方案都可以。

到目前为止，我一直在 this 工作。

谢谢！

【问题讨论】：

具体是什么问题？您用来检索数据的代码在哪里？展示您尝试过的内容
echo json_decode(file_get_contents($url))->bpi->USD->rate;

标签： javascript php jquery python json

【解决方案1】：

首先，有问题的json数据不是数组而是对象！

可视化任何一段 json 数据的简单方法是这样做

<?php
$j = '{"time":{"updated":"Oct 26, 2015 12:54:00 UTC","updatedISO":"2015-10-26T12:54:00+00:00","updateduk":"Oct 26, 2015 at 12:54 GMT"},"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":"283.9203","description":"United States Dollar","rate_float":283.9203},"GBP":{"code":"GBP","rate":"185.0732","description":"British Pound Sterling","rate_float":185.0732}}}';

print_r( json_decode($j) );

在这种情况下会产生：-

stdClass Object
(
    [time] => stdClass Object
        (
            [updated] => Oct 26, 2015 12:54:00 UTC
            [updatedISO] => 2015-10-26T12:54:00+00:00
            [updateduk] => Oct 26, 2015 at 12:54 GMT
        )

    [disclaimer] => This data was produced from the CoinDesk Bitcoin Price Index (USD). Non-USD currency data converted using hourly conversion rate from openexchang
erates.org
    [bpi] => stdClass Object
        (
            [USD] => stdClass Object
                (
                    [code] => USD
                    [rate] => 283.9203
                    [description] => United States Dollar
                    [rate_float] => 283.9203
                )

            [GBP] => stdClass Object
                (
                    [code] => GBP
                    [rate] => 185.0732
                    [description] => British Pound Sterling
                    [rate_float] => 185.0732
                )

        )

)

这很简单地告诉您a）它是一个对象，其属性也是对象等，以及b）如何引用对象中的任何属性。

所以要得到你想要的汇率，我会这样做：-

<?php
$j = '{"time":{"updated":"Oct 26, 2015 12:54:00 UTC","updatedISO":"2015-10-26T12:54:00+00:00","updateduk":"Oct 26, 2015 at 12:54 GMT"},"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":"283.9203","description":"United States Dollar","rate_float":283.9203},"GBP":{"code":"GBP","rate":"185.0732","description":"British Pound Sterling","rate_float":185.0732}}}';

$bitExchange = json_decode($j);

// the GBP exchange rate will be
echo $bitExchange->bpi->GBP->rate;
// or if you prefer
echo $bitExchange->bpi->GBP->rate_float;

【讨论】：

【解决方案2】：

假设json数据在python中存储在json_text，可以这样做

import json
json.loads(json_text).get('bpi').get('USD').get('rate')

如果数据对您很重要，您应该检查错误。此外，使货币可配置可能是一个好主意。

【讨论】：