使用json_decode在PHP中解析JSON对象

Question

我试图从提供JSON格式数据的Web服务请求天气。我的PHP请求代码失败了：

$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。为了简洁起见，一些细节已被截断，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

这似乎起作用：

$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，因此无法使用->语法。我还建议您安装JSONview
Firefox扩展
，以便您可以以类似于 Firefox显示XML结构的漂亮格式的树状视图查看生成的json文档。这使事情变得容易得多。