Handling PHP URL and GET requests

Question

I am currently parsing any given url, for example example.com/page/1 or example.com/api/info/1, by exploding the URL:

$REQ = explode('/', $_SERVER['REQUEST_URI']);
array_shift($REQ);
$REQ = array_filter($REQ, function($value) { return $value !== ''; });]

and then accessing its elements in the array like so:

if (count($REQ) > 1 && $REQ[0] == 'page' && $REQ[1] == '1'){
    \\ show page 1
}

But how could I handle (and access via array in the same way) a url that also includes GET elements, such as example.com/page?id=1 or example.com/api/info?=hello ?

I am using nginx and trying files like below:

location / {
    index index.php;
    try_files $uri /index.php?$query_string;
    }