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
Related
How can I create JSON using PHP with data which contains JSON without including a bunch of escape characters in the JSON, and without converting JSON first to an array or object, and then back to JSON?
<?php
/*
GIVEN: Data from DB contained in array $a.
I know that sometimes JSON shouldn't be stored in a DB, but please assume this is a good case for doing so.
*/
$a[0]=json_encode(['a'=>5,'b'=>'hello']);
$a[1]=json_encode(['a'=>2,'b'=>'how are you']);
$a[2]=json_encode(['a'=>7,'b'=>'goodby']);
$o=[
['x'=>321,'y'=>$a[0]],
['x'=>123,'y'=>$a[1]],
['x'=>111,'y'=>$a[2]],
];
echo('<pre>'.print_r($o,1).'</pre>');
echo(json_encode($o));
/*
Undesired result containing a bunch of escape characters. Granted, they are benign, however, will increase network trafic.
[{"x":321,"y":"{\"a\":5,\"b\":\"hello\"}"},{"x":123,"y":"{\"a\":2,\"b\":\"how are you\"}"},{"x":111,"y":"{\"a\":7,\"b\":\"goodby\"}"}]
*/
$o=[
['x'=>321,'y'=>json_decode($a[0])],
['x'=>123,'y'=>json_decode($a[1])],
['x'=>111,'y'=>json_decode($a[2])],
];
echo('<pre>'.print_r($o,1).'</pre>');
echo(json_encode($o));
/*
Desired result, however, is there a more efficient way to do this?
[{"x":321,"y":{"a":5,"b":"hello"}},{"x":123,"y":{"a":2,"b":"how are you"}},{"x":111,"y":{"a":7,"b":"goodby"}}]
*/
No, there is no faster way then to decode, mutate and encode again.
You could however combine the decoding code closely with your database queries. If you have a data model class, you would do the decoding there, so that the code that calls this service will never see the JSON, but always the decoded data.
Then, again, in the data model, where you write to the database, you would perform the JSON encoding at the last moment.
This way you hide the JSON factor behind the walls of the data layer, and the rest of the application will not have to be aware of that.
Manipulating JSON directly
Another solution consists of writing a library that can juggle with JSON, giving possibilities to set values inside JSON without the caller having to decode/encode. This option requires much more code (or you could find an existing library), and so it is not really my first recommendation. But here is a naive example of a function that could exist in that library:
function json_set($json, $path, $value) {
$arr = json_decode($json, true);
$ref =& $arr;
$props = explode("/", $path);
$finalProp = array_pop($props);
foreach ($props as $key) {
if (!isset($ref[$key])) $ref[$key] = [];
$ref =& $ref[$key];
}
$obj = json_decode($value);
$ref[$finalProp] = $obj ? $obj : $value;
return json_encode($arr);
}
This allows you to provide an existing JSON string, a path pointing to a certain spot inside that JSON, and a value that should be put there. That value could itself also be JSON.
Here is how you would use it in your case, given the JSON values in $a which you got from the database:
$o=json_encode([
['x'=>321],
['x'=>123],
['x'=>111],
]);
$o = json_set($o, '0/y', $a[0]);
$o = json_set($o, '1/y', $a[1]);
$o = json_set($o, '2/y', $a[2]);
echo $o;
Output:
[{"x":321,"y":{"a":5,"b":"hello"}},
{"x":123,"y":{"a":2,"b":"how are you"}},
{"x":111,"y":{"a":7,"b":"goodby"}}]
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;
{"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.
I want to get polygon coordinates from below String.
{"polygon":{"type":"Feature","properties":[],"geometry":{"type":"Polygon","coordinates":[[[-7302732.4720101,6527844.6333235],[-3193477.8319711,6606116.1502766],[-5111129.9973226,5001550.0527375],[-6637424.5779086,4884142.7773079],[-7772361.5737289,5158093.0866438],[-7302732.4720101,6527844.6333235]]]},"crs":{"type":"name","properties":{"name":"urn:ogc:def:crs:OGC:1.3:CRS84"}}}}
This is GeoJson string that i decode to array with below code:
$polygon = CJSON::decode($str);
when i want to get polygon i get error!
$var= $polygon->polygon;
or with below code:
$polygon = CJSON::decode($str,true);
$var = $polygon['polygon'];
although for getting coordinates:
foreach($polygon as $key=>$value)
$coordinates = $value['coordinates'];
or
$coordinates = $value[coordinates];
how can i get coordinates from geojson that i send from javascript to php for saving on postgresql with postgis?
$polygon->polygon->geometry->coordinates[0]
or
$polygon['polygon']['geometry']['coordinates'][0]
what you have is a multidimensional array/object not sure which its being output to when decoded in your case as it appears you have a class doing it I would have just used json_decode, but anyway. Yea from the looks of it, polygon is the main object, then in it is geometry which is an object that has type and coordinates, and then coordinates has multiple objects/arrays in it.
the above samples if I typed them right will show the first set of coordinates in that object. Of course you could run it through a loop ie:
In the case that it is an object assuming your Class decodes as an object and not an array. Not exactly sure what $polygon = CJSON::decode($str,true); does. But if its anything like json_decode() then you should be all set.
This is my method of breaking down the object as you present here, its worth noting you may want to check counts, and see if the object is set first, or if the property exists in the object to prevent other means of the code breaking down the road. But what I have here is just pure example at its core, it will server its purpose though. But will not error handle which is why I say you may want to elaborate further on it doing those checks.
Anyway heres my code:
<?php
$str = '{"polygon":{"type":"Feature","properties":[],"geometry":{"type":"Polygon","coordinates":[[[-7302732.4720101,6527844.6333235],[-3193477.8319711,6606116.1502766],[-5111129.9973226,5001550.0527375],[-6637424.5779086,4884142.7773079],[-7772361.5737289,5158093.0866438],[-7302732.4720101,6527844.6333235]]]},"crs":{"type":"name","properties":{"name":"urn:ogc:def:crs:OGC:1.3:CRS84"}}}}';
$polygon = json_decode($str);
echo'<pre>';print_r($polygon);echo'</pre>';
$set = 1;
foreach($polygon->polygon->geometry->coordinates[0] as $coordinates)
{
echo 'Set '.$set.': ';$set++;
echo $coordinates[0].','.$coordinates[1].'<br>';
}
?>
see it in action http://7pz.net/geojson-parse.php (scroll to the bottom)
This should give you an array of all the coordinates and print them out line by line:
$string = '{"polygon":{"type":"Feature","properties":[],"geometry":{"type":"Polygon","coordinates":[[[-7302732.4720101,6527844.6333235],[-3193477.8319711,6606116.1502766],[-5111129.9973226,5001550.0527375],[-6637424.5779086,4884142.7773079],[-7772361.5737289,5158093.0866438],[-7302732.4720101,6527844.6333235]]]},"crs":{"type":"name","properties":{"name":"urn:ogc:def:crs:OGC:1.3:CRS84"}}}}';
$json = json_decode($string);
$coords_array = $json->polygon->geometry->coordinates[0];
foreach($coords_array as $c_a) {
echo $c_a[0] . "," .$c_a[1] . "<br>";
}
Access with:
$coords_array[0];
$coords_array[1];
$coords_array[2];
etc.
Basically you can turn the JSON string into an object and access each element with the -> notation.
I usally use a site called http://jsonviewer.stack.hu/ to decode JSON and find the path I need, then simply write them out as they appear, as in as in the above - $json->polygon->geometry->coordinates;.
Try it out yourself on the site.
I'm trying to get the "screenshotUrls" string from this piece of json:
$request_url = 'http://itunes.apple.com/search?term=ibooks&country=us&entity=software&limit=1';
$json = file_get_contents($request_url);
$decode = json_decode($json, true);
echo $decode['results'][0]['screenshotUrls'];
But I get only text "Array"
What have I done wrong?
Try
var_dump($decode['results'][0]['screenshotUrls']);
IF you get 'Array' output by PHP that means that you're trying to echo an actual array (or the string 'Array'...). That means you need to get a specific index value.
Since $decode['results']['0']['screenshotUrls'] is an array, if you want just a string (say, delimited by commas), you could use
echo implode(",", $decode['results']['0']['screenshotUrls']);
This will iterate over the array, and return a comma-separated string of all the URLs.
Do a var_dump($decode['results']['0']['screenshotUrls']). You'll find that the ['screenshotUrls'] is actually an Array, containing one or more URLs (hence the plural 'urls' in its name).
There's nothing wrong with your code so far, but $decode['results'][0]['screenshotUrls'] is an array of all the URLs to screenshots. To go through each one individualy, you need to do:
forearch ($decode['results'][0]['screenshotUrls'] as $url) {
// Do stuff here
}