CODEWITHSUNDEEP
phpjsonparsinggoogle-maps-api-3elevation
user1077894
user1077894

Reputation: 31

Parse Results of Google Elevation Using PHP

I'm new to JSON and parsing. I get the following results when requesting an elevation from the Google Elevation API.

{
  "status": "OK",
  "results": [ {
    "location": {
      "lat": 39.7391536,
      "lng": -104.9847034
    },
    "elevation": 1608.8402100
  } ]
}

When parsing, I don't know how to effectively reference the elevation using the json_decode results. My abridged code is below:

$json_string = file_get_contents($url);
$parsed_json = json_decode($json_string);
$geoElevation = $parsed_json->{'elevation'};

Can anyone tell me why I can't access the "elevation" value using the above?

Upvotes: 3

Views: 1037

Answers (2)

Book Of Zeus
Book Of Zeus

Reputation: 49877

Try this:

$json_string = file_get_contents($url);
$parsed_json = json_decode($json_string);

echo $parsed_json->results[0]->elevation;

or if you prefer using array:

$json_string = file_get_contents($url);
$parsed_json = json_decode($json_string, TRUE);

echo $parsed_json['results'][0]['elevation'];

The second argument:

When TRUE, returned objects will be converted into associative arrays. from the json_encode manual

Upvotes: 4

mario
mario

Reputation: 145482

You should use print_r($parsed_json) to get a better visualization of your data structure:

$parsed_json
(
    [status] => OK
    [results] => Array
        (
            [0] => Array
                (
                    [location] => Array
                        (
                            [lat] => 39.739153600000001631542545510456
                            [lng] => -104.98470340000000078362063504755
                        )    
                    [elevation] => 1608.8402100000000700674718245864
                )
        )
)

This is an array, which you get by using json_decode($json_string, TRUE);. That makes it easier to traverse the entries.

In your case you want:

 print $parsed_json["results"][0]["elevation"];

Normally you would want to foreach over the numeric levels. But if you only expect one result, then [0] is perfectly fine to use.

Upvotes: 3

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