How can PHP beginners effectively troubleshoot and debug issues related to character encoding and input validation in their web development projects?

Issue: Character encoding and input validation are common issues in web development projects that can lead to security vulnerabilities and incorrect data processing. To effectively troubleshoot and debug these issues, PHP beginners can use functions like mb_convert_encoding() to handle character encoding and filter_input() to validate user input. Code snippet:

// Character encoding fix
$input = "Some input with special characters é";
$encoded_input = mb_convert_encoding($input, "UTF-8");

// Input validation fix
$user_input = filter_input(INPUT_POST, 'username', FILTER_SANITIZE_STRING);
if (!$user_input) {
    echo "Invalid username input";
}