How can debugging techniques be applied to identify and resolve issues with PHP session variables?

To identify and resolve issues with PHP session variables, debugging techniques can be applied by checking the session configuration, verifying session_start() is called before accessing session variables, and using var_dump() or print_r() to inspect the contents of session variables.

// Check session configuration
echo session_save_path(); // Check the session save path
echo session_name(); // Check the session name

// Verify session_start() is called before accessing session variables
session_start();

// Use var_dump() or print_r() to inspect session variables
var_dump($_SESSION);
print_r($_SESSION);