How can changes in PHP versions impact the functionality of existing scripts like surveys, and what steps can be taken to address these issues?

Changes in PHP versions can impact the functionality of existing scripts like surveys by introducing deprecated functions or syntax changes that may cause errors or unexpected behavior. To address these issues, it is important to update the script to use current PHP best practices and replace any deprecated functions with their modern equivalents.

// Example code snippet to address deprecated function usage
// Old code using deprecated function
$old_result = mysql_query($query);

// Updated code using mysqli function
$conn = mysqli_connect($hostname, $username, $password, $database);
$new_result = mysqli_query($conn, $query);