How to decode multi-layers nested JSON String and display in PHP?

Question

I know how to decode a JSON string and get the data from one dimensional array but how to get the data from the nested array? Below is my code:

$data = json_decode($json);

and below is the JSON return value:

{
      "area_metadata": [
        {
          "name": "A",
          "label_location": {
            "latitude": 1,
            "longitude": 1
          }
        },
        {
          "name": "B",
          "label_location": {
            "latitude": 1,
            "longitude": 1
          }
        }   
      ],
     "items": [
            {
              "update_timestamp": "2017-05-02T09:51:20+08:00",
              "timestamp": "2017-05-02T09:31:00+08:00",
              },
              "locations": [
                {
                  "area": "A",
                  "weather": "Showers"
                },
                {
                  "area": "B",
                  "weather": "Cloudy"
                }
              ]
            }
        ]}

I had tested:

echo $data->items->locations[0]->area;

but I got this error

Trying to get property of non-object

Also,I tried to convert JSON into array instead of object:

$data = json_decode($json,true);


if (isset($data)) 
{
    foreach ($data->items->locations as $location) 
    {
            if (empty($location["area"])) { continue; }
            if ($location["area"] == "A") 
            {
                echo $location["weather"];

            }


    }
}

but it also not working.

Could anyone can advise which step that I did wrongly? Thanks!

Edited: Below is the pastebin link with full JSON content. https://pastebin.com/cewszSZD

It appears that your JSON is malformed, are you sure this is the exact JSON string you are trying to decode? The decode might "fail" due to the malformed JSON. — Tom Udding, Jun 01 '17 at 17:16
Not responding to my question does not help solving your problem. I understand it if you cannot be here all the time, but people appreciate it if you respond a little sooner. — Tom Udding, Jun 01 '17 at 17:25
I missed out a "}", just added it back to the JSON Data.Thanks. — Json, Jun 01 '17 at 18:08
I didn't paste the whole JSON data here,cos it was very long,but the overall structure is similar. — Json, Jun 01 '17 at 18:13
@TomUdding Thanks for your prompt reply.I live in Asia time zone and it is midnight now,I will try my best to reply asap. — Json, Jun 01 '17 at 18:18
When you do: `$data = json_decode($json,true);` try to use `var_dump()` to se, how the arrays are formed. — uikolas, Jun 01 '17 at 18:50
Ah I see, no need to hurry then. It might be better if you provide the whole JSON string (either via a Gist or Pastebin). The edited JSON is still malformed. — Tom Udding, Jun 01 '17 at 18:50
@uikolas `var_dump` will return `NULL` for the provided JSON since it is malformed. — Tom Udding, Jun 01 '17 at 18:51
Yes, I know that. Maybe the author will post all json content. :) — uikolas, Jun 01 '17 at 18:53
Thanks, that JSON is valid, I'll write a sample code in a second. — Tom Udding, Jun 01 '17 at 19:06
Items is an array, not an object, you just need something like `echo $data->items[0]->locations[0]->area;` — TheGentleman, Jun 01 '17 at 19:15

Tom Udding · Accepted Answer · 2017-06-01T19:24:29.773

The JSON you provided (in your question) is malformed and using json_decode() on it will result in NULL. Thus nothing will happen when you try to access the decoded object because it doesn't exist.

The full JSON you provided is valid and the reason why your code didn't yield any results is because in items there is an "inner"-array:

(...) 
["items"] => array(1) {
    [0] => array(4) {
//  ^^^^^^^^^^^^^^^^^
        ["update_timestamp"] => string(25) "2017-05-02T09:21:18+08:00" 
        ["timestamp"] => string(25) "2017-05-02T09:07:00+08:00" 
        ["valid_period"] => array(2) { 
            ["start"] => string(25) "2017-05-02T09:00:00+08:00" 
            ["end"] => string(25) "2017-05-02T11:00:00+08:00" 
        } 
        ["forecasts"] => array(47) { 
            [0] => array(2) { 
                ["area"] => string(10) "Ang Mo Kio" 
                ["forecast"] => string(19) "Partly Cloudy (Day)" 
            }
            (...)

You'll have to access that array through key 0, for arrays it will look like this:

$data = json_decode($json, true);
echo $data['items'][0]['forecasts'][0]['area'];
//                 ^^^

And for objects like this:

$data = json_decode($json);
echo $data->items[0]->forecasts[0]->area;
//               ^^^

The second 0 changes the location (the different arrays in the forecasts array).

You can check the output here (array approach) and here (object approach).

score 0 · Answer 2 · answered Jun 01 '17 at 19:16

0

It would be easier to help if you post all the JSON data or link to a screenshot of it. Try:

$items[0]['locations'][0]['area'];

Single quotes on strings, no quotes on numbers.

answered Jun 01 '17 at 19:16

Bman70

743
5
11

You could put all the areas in an array with: `$areas = array(); foreach($data['items'] as $area) $areas[] = $area['forecasts'][0]['area'];` – Bman70 Jun 01 '17 at 20:02

How to decode multi-layers nested JSON String and display in PHP?

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