How can a beginner differentiate between functional and non-functional PHP code?

A beginner can differentiate between functional and non-functional PHP code by understanding that functional code performs a specific task or function, while non-functional code may contain errors or not produce the desired outcome. To ensure code functionality, beginners should test their code thoroughly and debug any issues that arise.

// Functional PHP code example
function addNumbers($num1, $num2) {
    return $num1 + $num2;
}

$result = addNumbers(5, 3);
echo $result; // Output: 8