Nested PHP arrays to json

Question

So my code here:

 $featurecollection = ("FeatureCollection");
 $test[] = array (
 "type" => $featurecollection,
 $features[] = array($images)
 );
 file_put_contents($cache,json_encode($test));

results in the following json:

[
 {
 "type":"feature",
 "0":[
 [
 {
 "title":"some title",
 "src":"value",
 "lat":"value",
 "lon":"value"
 },
 {
 "title":"some title",
 ...

But I need to nest things differently and I'm perplexed on how the php array should be constructed in order to get a result like:

{
"type":"FeatureCollection",
 "features":[
 {
 "type":"Feature",
 "geometry":{
 "coordinates":[
 -94.34885,
 39.35757
 ],
 "type":"Point"
 },
 "properties":{
 "latitude":39.35757,
 "title":"Kearney",
 "id":919,
 "description":"I REALLY need new #converse, lol. I've had these for three years. So #destroyed ! :( Oh well. Can't wait to get a new pair and put my #rainbow laces through. #gay #gaypride #bi #proud #pride #colors #shoes #allstar #supporting ",
 "longitude":-94.34885,
 "user":"trena1echo5",
 "image":"http://images.instagram.com/media/2011/09/09/ddeb9bb508c94f2b8ff848a2d2cd3ece_7.jpg",
 "instagram_id":211443415
 }
 },

What would the php array look like for that? I'm thrown off by the way everything is nested but still has a key value.

• Matt Ball: I think you just need to replace $features[] = array($images) with 'features' => array($images), though I'm pretty n00b w/PHP...

Answer 1

Here's how I'd represent that in PHP:

array(
 'type' => 'FeatureCollection',
 'features' => array(
 array(
 'type' => 'Feature',
 'geometry' => array(
 'coordinates' => array(-94.34885, 39.35757),
 'type' => 'Point'
 ), // geometry
 'properties' => array(
 // latitude, longitude, id etc.
 ) // properties
 ), // end of first feature
 array( ... ), // etc.
 ) // features
)

So to get that structure, each feature has to be an associative array of:

• type,
• geometry - an associative array of:
  • coordinates - an indexed array of values,
  • type
• properties - an associative array of values like latitude, longitude, id etc.

It's times like these when I prefer languages that distinguish between lists (array(1, 2, 3)) and dictionaries or maps (array('a' => 1, 'b' => 2)).

• Michael C.: Okay so how do I loop through those variables (to create multiple features)? I get how to build this array and then encode it to json, I'm just stumped on how to build it with multiple instances.
• Ross: Where are you getting your data from (and in what structure)? I'd create a new question with this info to get faster responses :)

Answer 2

With PHP 5.4 and above:

$array = [
 'type' => 'FeatureCollection',
 'features' => [
 [
 'type' => 'Feature',
 'geometry' => [
 'coordinates' => [-94.34885, 39.35757],
 'type' => 'Point'
 ], // geometry
 'properties' => [
 // latitude, longitude, id etc.
 ] // properties
 ], // end of first feature
 [] // another feature, and so on
 ] // end of features
];

For the PHP script below:

<?php
header('Content-type=> application/json');
echo json_encode($array);

This is the JSON output;

{
 "type": "FeatureCollection",
 "features": [
 {
 "type": "Feature",
 "geometry": {
 "coordinates": [
 -94.34885,
 39.35757
 ],
 "type": "Point"
 },
 "properties": []
 },
 []
 ]
}