How can separating PHP code from string concatenation improve code readability and functionality?

Separating PHP code from string concatenation improves code readability by making it easier to distinguish between logic and presentation. It also enhances functionality by allowing for easier debugging and maintenance of the code. By keeping PHP code separate, it becomes simpler to modify and reuse the logic without having to navigate through concatenated strings.

// Before separating PHP code from string concatenation
echo "Hello, " . $username . "! Your balance is $" . $balance;

// After separating PHP code from string concatenation
$message = "Hello, " . $username . "! Your balance is $";
echo $message . $balance;