What are the potential issues with handling checkbox data in PHP, and how can they be avoided?

Issue: One potential issue with handling checkbox data in PHP is that unchecked checkboxes do not get submitted with the form data, leading to inconsistencies in processing the data. To avoid this issue, you can use isset() function to check if the checkbox value is set in the form data.

// Check if the checkbox is checked
$checkbox_value = isset($_POST['checkbox_name']) ? $_POST['checkbox_name'] : '';