解析JSON不工作

Question

我是新來的JSON和我使用json_encode創建一個JSON對象，看起來像這樣

[{ 
     "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" 
}] 

我試圖解析以下使用腳本數據

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

    }); 

我不知道我在這裏做錯了什麼。我知道在JavaScript中默認長度爲0，所以我如何獲得這個值？ BTW的var_dump在$ jsondata給出了數據

Answer 1

你打電話console.log(jsonData.timestamp[0]);這基本上意味着，在jsonData找到屬性時間戳，這是一個數組並獲得第一個索引。

但jsonData是數組，而不是時間戳。你可能應該像console.log(jsonData[0].timestamp);

Answer 2

在這裏嘗試使用單引號：

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

替換有：

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

因爲$jsondata包含雙引號（"），字符串傳遞給JSON.parse()將被打破，導致JavaScript無效。

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

此外，你不正確的訪問對象：

jsonData.timestamp[0]; 

應該是：

jsonData[0].timestamp; 

您的JSON是時間戳對象的數組，所以使用數組索引[0]，首先。

Answer 3

您的JSON數據包括"個字符。您正在嘗試將其注入到以"分隔的JavaScript字符串文字中，但您並未轉義數據中的"字符。

您的JSON還包含新行，JavaScript字符串中不允許使用文字換行，因此您需要用換碼序列（\n）替換它們。

也就是說，JSON是JavaScript文字語法的一個子集，因此您不需要將JSON文本轉換爲JavaScript字符串文字然後解析它，您可以簡單地使用JSON作爲JavaScript ：

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

---

您有另一個問題。您的JSON數據表示一個對象數組，而不是具有數組作爲屬性值的對象。您需要訪問之前的屬性名稱：data[0].timestamp。