Question

我是JSON的新手，我使用json_encode创建一个看起来像这样的JSON对象

[{
      "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"
}]

我尝试使用下面的脚本解析数据

$(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javascript中默认长度为0，所以如何获取值？ $ jsondata上的BTW var_dump给出了数据

Answer 1

您的JSON数据包含"个字符。您正尝试将其注入由"分隔的JavaScript字符串文字，但您不能转义数据中的"个字符。

您的JSON还包含新行，JavaScript字符串中不允许使用新的行，因此您需要使用转义序列（\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的：

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

你还有另外一个问题。您的JSON数据表示对象数组，而不是具有数组作为属性值的对象。您需要在属性名称之前访问数组：data[0].timestamp。

Answer 2

请尝试使用单引号：

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

将其替换为：

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

由于$jsondata包含双引号（"），因此传递给JSON.parse()的字符串将被破坏，导致JavaScript无效。

然而，正如昆汀回答的那样，整个JSON.parse是不必要的 Like he answered，请使用：var data = <?php echo $jsondata; ?>;

此外，您正在错误地访问该对象：

jsonData.timestamp[0];

应该是：

jsonData[0].timestamp;

您的JSON是一个时间戳对象数组，因此首先使用数组索引[0]。

Answer 3

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

但是jsonData是数组，而不是时间戳。您可能应该使用类似console.log(jsonData[0].timestamp);

的内容

解析json无法正常工作

3 个答案: