Laravel如何确定_GET

I'm still very new at Laravel.

I got problem how can I use Isset($_GET)?

How to get for example: http://virtualhost.com/flytrap/public/location?city=25?

Usually when at pure PHP, I always use:

if (isset($_GET["submit"]))
{
   $location = $_GET["city"];
}

to get city value. So I can use it for query at database. If I use Core PHP method I got an error.

You can use below code

$location = Request::query('city', false); //insed of $_GET['city'];

This is Laravel equivalent (see http://laravel.com/docs/4.2/requests):

if (Input::has('submit')) {
    $location = Input::get('city');
}

But as Lalit Sharma says, you should maybe always set $location even if you have not "submit" in GET:

$location = Input::get('city', null);

null is the default value so you can ommit it or use any other value:

$location = Input::get('city', 'Reykjavik');