How can PHP developers ensure that their code is elegant and efficient when manipulating numbers?

To ensure that PHP code manipulating numbers is elegant and efficient, developers can use built-in functions like `intval()`, `floatval()`, and `number_format()` to handle conversions and formatting. Additionally, using arithmetic operators like `+`, `-`, `*`, and `/` instead of complex logic can simplify calculations. Lastly, optimizing code by avoiding unnecessary loops or nested conditions can improve efficiency.

// Example of using built-in PHP functions to manipulate numbers elegantly and efficiently

$number = "123.45";

// Convert string to integer
$integerValue = intval($number);

// Convert string to float
$floatValue = floatval($number);

// Format number with 2 decimal places
$formattedNumber = number_format($number, 2);

echo $integerValue . "\n";
echo $floatValue . "\n";
echo $formattedNumber . "\n";