What are the potential issues when trying to pass a complete string as a GET variable in PHP?

When trying to pass a complete string as a GET variable in PHP, the string may contain special characters that can interfere with the URL structure and cause unexpected behavior. To solve this issue, you can encode the string using the `urlencode()` function before appending it to the URL. This will ensure that the string is properly formatted and can be safely passed as a GET variable.

$string = "This is a complete string with special characters!@#$";
$encodedString = urlencode($string);
$url = "example.com/script.php?data=" . $encodedString;

// In the script.php file, you can decode the string using urldecode()
$decodedString = urldecode($_GET['data']);
echo $decodedString;