What are the potential pitfalls of trying to access dropdown values in PHP before submitting a form?

Potential pitfalls of trying to access dropdown values in PHP before submitting a form include trying to access values that have not been selected yet, leading to errors or unexpected behavior. To solve this, ensure that the form has been submitted before trying to access the dropdown values in PHP.

if ($_SERVER["REQUEST_METHOD"] == "POST") {
    $selected_value = $_POST["dropdown_name"];
    // Use the selected dropdown value here
}