Question

I am creating pages that are dependent on a query in the url (eg europe.php?country=france). I am aware that it will be useful to re-write theses as europe.php/france with htaccess for SEO etc but what if that page is accessed without the query string?

I am using php to $_GET the query, so if I access the page without the query I get ‘var=;’ ie, it is empty (and retrieves an error). I’m trying to use an if statement to check if the $_GET retrieves nothing but am unsure if this is the right thing to do.

So: how do I check for an un-retrieved var so I can set a default?
Or: am I going about this the wrong way?

Answer 1

If you know the index into $_GET, use isset():

$country = 'default';
if( isset( $_GET['country'])) {
    $country = $_GET['country'];
}

This will only test if the country parameter was passed, but it could have been set to an empty string. If this is invalid input, you can combine the check using empty():

$country = 'default';
if( isset( $_GET['country']) && !empty( $_GET['country'])) {
    $country = $_GET['country'];
}

You can condense this into one line and save the result to a variable $country using the ternary operator, like so:

$country = (isset( $_GET['country']) && !empty( $_GET['country'])) ? $_GET['country'] : 'default';

Finally, you can check if you got absolutely no $_GET parameters by calling count() on $_GET:

if( count( $_GET) == 0) {
    die( "No parameters - Invalid input!");
}