使用json_decode在PHP中解析JSON对象

Question

我试图通过提供JSON格式数据的Web服务请求天气.我的PHP请求代码没有成功,是:

$url="http://www.worldweatheronline.com/feed/weather.ashx?q=schruns,austria&format=json&num_of_days=5&key=8f2d1ea151085304102710";
$json = file_get_contents($url);
$data = json_decode($json, TRUE);
echo $data[0]->weather->weatherIconUrl[0]->value;    

这是返回的一些数据.为简洁起见,部分细节已被截断,但保留了对象完整性:

{ "data": 
    { "current_condition": 
        [ { "cloudcover": "31",
            ... } ],  
      "request": 
        [ { "query": "Schruns, Austria",
            "type": "City" } ],
      "weather": 
        [ { "date": "2010-10-27",
            "precipMM": "0.0",
            "tempMaxC": "3",
            "tempMaxF": "38",
            "tempMinC": "-13",
            "tempMinF": "9",
            "weatherCode": "113",
            "weatherDesc": [ {"value": "Sunny" } ],
            "weatherIconUrl": [ {"value": "http:\/\/www.worldweatheronline.com\/images\/wsymbols01_png_64\/wsymbol_0001_sunny.png" } ],
            "winddir16Point": "N",
            "winddirDegree": "356",
            "winddirection": "N",
            "windspeedKmph": "5",
            "windspeedMiles": "3" }, 
          { "date": "2010-10-28",
            ... },

          ... ]
        }
    }
}

Answer 1

这似乎有效:

$url = 'http://www.worldweatheronline.com/feed/weather.ashx?q=schruns,austria&format=json&num_of_days=5&key=8f2d1ea151085304102710%22';
$content = file_get_contents($url);
$json = json_decode($content, true);

foreach($json['data']['weather'] as $item) {
    print $item['date'];
    print ' - ';
    print $item['weatherDesc'][0]['value'];
    print ' - ';
    print '<img src="' . $item['weatherIconUrl'][0]['value'] . '" border="0" alt="" />';
    print '<br>';
}

如果将json_decode的第二个参数设置为true,则会得到一个数组,因此您无法使用 - >语法.我还建议您安装JSONview Firefox扩展,这样您就可以在一个很好的格式化树视图中查看生成的json文档,类似于 Firefox显示XML结构的方式.这使事情变得容易多了.

Answer 2

如果您使用以下代码:

$json = file_get_contents($url);
$data = json_decode($json, TRUE);

TRUE返回一个数组而不是一个对象.

Answer 3

试试这个例子

$json = '{"foo-bar": 12345}';

$obj = json_decode($json);
print $obj->{'foo-bar'}; // 12345

http://php.net/manual/en/function.json-decode.php

NB - 两个负面因素是积极的.:)