php traverse object using variables for property names - php

Question

I have a case where I may recive one of two json objects, in this case from either the google geocode api, or the places api.
Acccessing values from the geocoding api it will look like this:
$coordinates = $data->results[0]->geometry->location;
$cache_value['lat'] = (string) $coordinates->lat;
$cache_value['lng'] = (string) $coordinates->lng;
and an almost identical structure for places.
$coordinates = $data->result->geometry->location;
$cache_value['lat'] = (string) $coordinates->lat;
$cache_value['lng'] = (string) $coordinates->lng;
In my code I've two functions to handle each case, but they are almost idential with the exception of the result vs results[0] and I'd like to combine them. I've tried to passing a varriable but it throws errors:
$result = ($place) ? 'result' : 'results[0]';
$coordinates = $data->$result->geometry->location;
Gives the following:
Notice: Undefined property: stdClass::$result[0]
I'd like to know the correct syntax to achive what im after, and any pointers on nominclature, as Im afraid this question title is a bit inpercise.

Answer 1

Just do:
$result = $place ? $data->result : $data->results[0];
$coordinates = $result->geometry->location;
What your code is doing, is this: It tries to resolve a property of $data object with a name of results[0], and there is none; Once again - it does not resolve 0 index of the results property, but it tries to find a property with a literal name results[0]; It would work if your object looked like this:
$obj = (object)array( 'results[0]' => 'hey there' );
If for any reason you would like to play with that, you could create a silly property like this: $data->{'results[0]'} = 5; - but it's stupid, don't do that :)

Answer 2

i believe php is looking for a key named results[0], its not smart enough to know that the properties name is results and you want the first member of the collection [0]

Answer 3

The issue is the reference of the variable name, rather than its value.
$result = ($place) ? 'result' : 'results[0]';
$coordinates = $data->$result->geometry->location;
$result is just a string and should be the actual value of either $data->result or $data->result[0].
To correct it, simply use $result to hold the value of result.
$result = ($place) ? $data->result : $data->results[0];
$coordinates = $result->geometry->location;