Access JSON values in PHP - php

{"coord":{"lon":73.69,"lat":17.8},"sys":{"message":0.109,"country":"IN","sunrise":1393032482,"sunset":1393074559},"weather":[{"id":800,"main":"Clear","description":"Sky is Clear","icon":"01n"}],"base":"cmc stations","main":{"temp":293.999,"temp_min":293.999,"temp_max":293.999,"pressure":962.38,"sea_level":1025.86,"grnd_level":962.38,"humidity":78},"wind":{"speed":1.15,"deg":275.503},"clouds":{"all":0},"dt":1393077388,"id":1264491,"name":"Mahabaleshwar","cod":200}
I am trying to fetch description from the weather from the json above but getting errors in php. I have tried the below php code:
$jsonDecode = json_decode($contents, true);
$result=array();
foreach($jsonDecode as $data)
{
foreach($data{'weather'} as $data2)
{
echo $data2{'description'};
}
}
Any help is appreciated. I am new in using json.

You have to use square brackets ([]) for accessing array elements, not curly ones ({}).
Thus, your code should be changed to reflect these changes:
foreach($data['weather'] as $data2)
{
echo $data2['description'];
}
Also, your outer foreach loop will cause your code to do something completely different than you intend, you should just do this:
foreach($jsonDecode['weather'] as $data2)
{
echo $data2['description'];
}

Your $jsonDecode seems to be an array, so this should work-
foreach($jsonDecode['weather'] as $data)
{
echo $data['description'];
}

You can access data directly with scopes
$json = '{"coord":{"lon":73.69,"lat":17.8},"sys":{"message":0.109,"country":"IN","sunrise":1393032482,"sunset":1393074559},"weather":[{"id":800,"main":"Clear","description":"Sky is Clear","icon":"01n"}],"base":"cmc stations","main":{"temp":293.999,"temp_min":293.999,"temp_max":293.999,"pressure":962.38,"sea_level":1025.86,"grnd_level":962.38,"humidity":78},"wind":{"speed":1.15,"deg":275.503},"clouds":{"all":0},"dt":1393077388,"id":1264491,"name":"Mahabaleshwar","cod":200}';
$jsonDecode = json_decode($json, true);
echo $jsonDecode['weather'][0]['description'];
//output Sky is Clear
As you can see wheater` is surrounded with scopes so that means it is another array. You can loop throw that array if you have more than one result
foreach($jsonDecode['weather'] as $weather)
{
echo $weather['description'];
}
Live demo

If the result of decode is an array, use:
$data['weather']
If the result is an object, use:
$data->weather

you have to access "weather" with "[]" operator
like this,
$data["weather"]

There is several things worth answering in your question:
Q: What's the difference between json_decode($data) and json_decode($data, true)?
A: The former converts JSON object to a PHP object, the latter creates an associative array: http://uk1.php.net/json_decode
In either case, there is no point on iterating over the result. You probably want to access just the 'weather' field:
$o = json_decode($data) => use $weather = $o->weather
$a = json_decode($data, true) => use $weather = $a['weather']
Once you have the 'weather' field, look carefully what it is:
"weather":[{"id":800,"main":"Clear","description":"Sky is Clear","icon":"01n"}]
It's an array, containing a single object. That means you will either need to iterate over it, or use $clearSky = $weather[0]. In this case, it does not matter which approach of json_decode did you choose => JSON array is always decoded to a PHP (numeric indexed) array.
But, once you get $clearSky, you are accessing the object and it again matters, which approach you chose - use arrow or brackets, similarly to the first step.
So, the correct way to get for exaple the weather description would be either of these:
json_decode($data)->weather[0]->description
json_decode($data, true)['weather'][0]['description']
Note: In the latter case, dereferencing result of the function call is supported only in PHP 5.4 or newer. In PHP 5.3 or older, you have to create a variable.
Note: I also encourage you to always check if the expected fields are actually set in the result, using isset. Otherwise you will try to access undefined field, which raises an error.

Related

Finding titles in JSON

I currently have this large JSON file: hastebin
But just want the titles of the posts.
I've tried this...
$json = $page;
$o = json_decode($json, true);
echo($json);
$titles = $o["*"]["*"]["*"]["*"]["title"];
var_dump($titles);
But it isn't working - it's returning NULL! Sometimes it just doesn't return anything.
If anyone is wondering, yes this is from Reddit.
This should do it:
$titles = array_map(function($post) {
return $post['data']['title'];
}, $o['data']['children']);
I'm not sure what you expected using "x" indices, but you should probably read about arrays.
PHP can't use wildcards like * in array keys. Whatever string you use to reference the key, it's going to try to find a key with that exact string. So what you tried can't work because there aren't any * keys.
You can get it by iterating all the levels, or iterating the outer level and referring to the proper nested key. But if you're just looking for all instances of 'title' a recursive method may be an easier way to get them.
array_walk_recursive($o, function($value, $key) use (&$titles) {
if ($key == 'title') $result[] = $value;
});
var_dump($titles);
This will get any value of 'title' regardless of its depth in the array, so if that's not what you want, then you'll need to iterate it and specifically reference the proper ones.
It's very hard to deal directly with such a long JSON document. The returned result from the page is not a valid JSON. It contains some HTML tags, but if you take the posts data and insert it in a file you can do the following according to the structure of your JSON (You can find your JSON in an external link here):
<?php
header("Content-Type:application/json");
$posts=file_get_contents('json.php');
//decode your JSON STRING
$posts=json_decode($posts,true);
//create a title variable to store your titles
$titles=array();
foreach($posts['data']['children'] as $child)
{
array_push($titles,$child['data']['title']);
}
echo json_encode($titles);
?>
You can even use this approach using a URL but ensure that it will return a valid JSON with no html

Read nested json in php

I know others have already asked about this, but I don't find a solution for my problem. In my PHP page I call an external service and I can't modify the response obtained.
I'm moving my first steps both with JSON and PHP.
The response is a JSON like this, I print this using the var_dump method:
object(stdClass)#1 (3)
{
["search_string"]=>string(15) "ABCDEFG HI LMNO"
["resut"]=>string(5) "apixi"
["0"]=>array(1){
[0]=>object(stdClass)#2(2){
["resp_code"]=>string(7) "12.34.0"
["resp_description"]=>string(15) "ABCDEFG HI LMNO"
}
}
}
In my PHP page I can read the value ”ABCDEFG HI LMNO” for the key "search_string" with this code, in the $output variable I store the result of the cUrl call
.......
$output = curl_exec($ch);
$jsonDecode =json_decode(str_replace('""','"',$output));
var_dump($jsonDecode);
echo $jsonDecode -> search_string;
I need the str_replace method because the JSON is dirty but not always, how can I access at the fields "resp_code" and "resp_description" and then store them in a variable? I tried many solutions but none works for me.
Instead of converting JSON array to stdClass object you can also convert it to regular PHP array by adding second parameter to the json_decode function:
$jsonDecode =json_decode(str_replace('""','"',$output), true);
In your case in the output, you'll get a multidimensional array.
Then, to access resp_code and resp_description, you can do something like this:
$respCode = $jsonDecode[0]["resp_code"];
$respDescription = $jsonDecode[0]["resp_description"];
In the decoded JSON you have, the resp_code and resp_description keys are difficult to get to, because the top-level object has a numerical ("0") attribute. Trying to reach that attribute like this:
$jsonDecode -> 0
will give this parsing error:
syntax error, unexpected '0' (T_LNUMBER), expecting identifier (T_STRING) or variable (T_VARIABLE) or '{' or '$'
Trying the same with a string notation (-> "0") also fails.
However, the suggestion in the error message is useful: encapsulate the zero with braces. Then you can proceed easily by adding the array index selector ([0]) to get to the object and keys of your interest, like this:
echo $jsonDecode->{0}[0]->resp_code;
echo $jsonDecode->{0}[0]->resp_description;
If you expect more elements in that array $jsonDecode->{0}, then loop over them like this:
foreach ($jsonDecode->{0} as $element) {
echo $element->resp_code;
echo $element->resp_description;
}
Alternative
If, however, you prefer to work with associative arrays instead of objects, you can use the second argument of json_encode as stated in the docs:
assoc
When TRUE, returned objects will be converted into associative arrays.
So then you would pass true as second argument:
$jsonDecode = json_decode(str_replace('""', '"', $output), true);
The above code would then be rewritten like this to access the variable as an associative array:
foreach ($jsonDecode[0] as $element) {
echo $element["resp_code"];
echo $element["resp_description"];
}

How to access complex JSON data in PHP

Here is the JSON response in which I need your help.
I need to access "age" key inside 'attribute'.
I really tried every possible ways that i could get. So can u please try to help me out :)
Another option, is that when you call json_decode by default you get a php object, however, if you add an optional boolean parameter you get an array which can be easier in situations like this to access nested elements.
// $data is the original json string
$json = json_decode($data, true);
print_r($json);
There are 2 ways I can see checking the json you just provided, one is by iterating the array, and the other one is accessing it by index:
$json = json_decode($response);
foreach ($json as $item) {
$value = $item->item->attribute->age->value;
var_dump($value);
}
the other way:
$value = $json[0]->item->attribute->age->value;

In PHP, filter an Array of Associative Arrays

In PHP, are there any inbuilt functions to turn
[{"id":1, "name":"John"}, {"id":2, "name":"Tim"}]
into
[{"id":1}, {"id":2}]
?
I've used JSON to describe the objects above, but that's just a conceptual representation of my array of associative arrays. I don't want to have to loop manually - something short and elegant I can fit on one line would be nice.
One line, using array_map:
$arr = json_decode('[{"id":1, "name":"John"}, {"id":2, "name":"Tim"}]');
$new_arr = array_map(function($el){$ret=array("id"=>$el->id);return $ret;},$arr);
var_dump(json_encode($new_arr));
array_map(function($arr){return $arr[0];}, $array);
This should do it.
Edit As noted by Jonathon Hibbard, you could pass array element by reference, this way you do not to assign result of the function and just use changed old array. The code should then be modified appropriately.
First decode json by json_decode. You will get an array. Then follow this link to remove an index from an associative array. Then again decode it. It should work.
do something like:
$array = json_decode($some_json_string, true);
array_walk($array, function($value, $key) use(&$array) {
if($key == "name") {
unset($array[$key]);
}
});
Edit:
Cthulhu's answer won't get ya there without re-assigning it. Could use it as a reference though (equal to the walk. though if you want to use the map, its a bit better not to reallocate with a brand new array copy and just pass it by reference, then remove the key with an unset within it and move on.)
array_map(function(&$array) { unset($array['name']; }, $array);

How to decode the following code in Json?

I'm trying to decode the following JSON using php json_decode function.
[{"total_count":17}]
I think the square brackets in output is preventing it. How do I get around that? I can't control the output because it is coming from Facebook FQL query:
https://api.facebook.com/method/fql.query?format=json&query=SELECT%20total_count%20FROM%20link_stat%20WHERE%20url=%22http://www.apple.com%22
PHP's json_decode returns an instance of stdClass by default.
For you, it's probably easier to deal with array. You can force PHP to return arrays, as a second parameter to json_decode:
$var = json_decode('[{"total_count":17}]', true);
After that, you can access the variable as $result[0]['total_count']
See this JS fiddle for an example of how to read it:
http://jsfiddle.net/8V4qP/1
It's basically the same code for PHP, except you need to pass true as your second argument to json_decode to tell php you want to use it as associative arrays instead of actual objects:
<?php
$result = json_decode('[{"total_count":17}]', true);
print $result[0]['total_count'];
?>
if you don't pass true, you would have to access it like this: $result[0]->total_count because it is an array containing an object, not an array containing an array.
$json = "[{\"total_count\":17}]";
$arr = Jason_decode($json);
foreach ($arr as $obj) {
echo $obj->total_count . "<br>";
}
Or use json_decode($json, true) if you want associative arrays instead of objects.

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