解析JSON不工作

Question

我是新来的JSON和我使用json_encode创建一个JSON对象，看起来像这样

[{ 
     "timestamp": "12\/16\/2013 0:00", 
     "curr_property": "7211", 
     "curr_property_cost": "123", 
     "day_property": "48", 
     "day_property_cost": "281", 
     "curr_solar_generating": "4958", 
     "curr_solar_export": "0", 
     "day_solar_generated": "33", 
     "day_solar_export": "0", 
     "curr_chan1": "1964", 
     "curr_chan2": "4958", 
     "curr_chan3": "289", 
     "day_chan1": "13", 
     "day_chan2": "33", 
     "day_chan3": "1" 
    }, { 
     "timestamp": "12\/16\/2013 0:00", 
     "curr_property": "7179", 
     "curr_property_cost": "123", 
     "day_property": "72", 
     "day_property_cost": "281", 
     "curr_solar_generating": "4926", 
     "curr_solar_export": "0", 
     "day_solar_generated": "49", 
     "day_solar_export": "0", 
     "curr_chan1": "1980", 
     "curr_chan2": "4926", 
     "curr_chan3": "273", 
     "day_chan1": "19", 
     "day_chan2": "49", 
     "day_chan3": "2" 
    }, { 
     "timestamp": "12\/16\/2013 0:00", 
     "curr_property": "9627", 
     "curr_property_cost": "165", 
     "day_property": "104", 
     "day_property_cost": "282", 
     "curr_solar_generating": "4749", 
     "curr_solar_export": "0", 
     "day_solar_generated": "65", 
     "day_solar_export": "0", 
     "curr_chan1": "1980", 
     "curr_chan2": "4749", 
     "curr_chan3": "2898", 
     "day_chan1": "26", 
     "day_chan2": "65", 
     "day_chan3": "12" 
    }, { 
     "timestamp": "12\/16\/2013 0:00", 
     "curr_property": "9610", 
     "curr_property_cost": "165", 
     "day_property": "136", 
     "day_property_cost": "282", 
     "curr_solar_generating": "4781", 
     "curr_solar_export": "0", 
     "day_solar_generated": "81", 
     "day_solar_export": "0", 
     "curr_chan1": "1980", 
     "curr_chan2": "4781", 
     "curr_chan3": "2849", 
     "day_chan1": "32", 
     "day_chan2": "81", 
     "day_chan3": "21" 
    }, { 
     "timestamp": "12\/16\/2013 0:01", 
     "curr_property": "9691", 
     "curr_property_cost": "166", 
     "day_property": "168", 
     "day_property_cost": "283", 
     "curr_solar_generating": "4797", 
     "curr_solar_export": "0", 
     "day_solar_generated": "97", 
     "day_solar_export": "0", 
     "curr_chan1": "1996", 
     "curr_chan2": "4797", 
     "curr_chan3": "2898", 
     "day_chan1": "39", 
     "day_chan2": "97", 
     "day_chan3": "31" 
    }, { 
     "timestamp": "12\/16\/2013 0:01", 
     "curr_property": "7034", 
     "curr_property_cost": "120", 
     "day_property": "191", 
     "day_property_cost": "283", 
     "curr_solar_generating": "4781", 
     "curr_solar_export": "0", 
     "day_solar_generated": "113", 
     "day_solar_export": "0", 
     "curr_chan1": "1980", 
     "curr_chan2": "4781", 
     "curr_chan3": "273", 
     "day_chan1": "46", 
     "day_chan2": "113", 
     "day_chan3": "32" 
}] 

我试图解析以下使用脚本数据

$(document).ready(
     function() { 
      var jsonData = JSON.parse("<?php echo $jsondata; ?>"); 
      console.log(jsonData.timestamp[0]);    

    }); 

我不知道我在这里做错了什么。我知道在JavaScript中默认长度为0，所以我如何获得这个值？ BTW的var_dump在$ jsondata给出了数据

Answer 1

你打电话console.log(jsonData.timestamp[0]);这基本上意味着，在jsonData找到属性时间戳，这是一个数组并获得第一个索引。

但jsonData是数组，而不是时间戳。你可能应该像console.log(jsonData[0].timestamp);

Answer 2

在这里尝试使用单引号：

var jsonData = JSON.parse("<?php echo $jsondata; ?>"); 

替换有：

var jsonData = JSON.parse('<?php echo $jsondata; ?>'); 

因为$jsondata包含双引号（"），字符串传递给JSON.parse()将被打破，导致JavaScript无效。

但是，正如Quentin回答的那样，整个JSON.parse是不必要的。
Like he answered，使用方法：var data = <?php echo $jsondata; ?>;

此外，你不正确的访问对象：

jsonData.timestamp[0]; 

应该是：

jsonData[0].timestamp; 

您的JSON是时间戳对象的数组，所以使用数组索引[0]，首先。

Answer 3

您的JSON数据包括"个字符。您正在尝试将其注入到以"分隔的JavaScript字符串文字中，但您并未转义数据中的"字符。

您的JSON还包含新行，JavaScript字符串中不允许使用文字换行，因此您需要用换码序列（\n）替换它们。

也就是说，JSON是JavaScript文字语法的一个子集，因此您不需要将JSON文本转换为JavaScript字符串文字然后解析它，您可以简单地使用JSON作为JavaScript ：

var data = <?php echo $jsondata; ?>; 

---

您有另一个问题。您的JSON数据表示一个对象数组，而不是具有数组作为属性值的对象。您需要访问之前的属性名称：data[0].timestamp。