What are best practices for handling different units of measurement when calculating distances in PHP functions?

When handling different units of measurement when calculating distances in PHP functions, it is best practice to convert all measurements to a consistent unit before performing any calculations. This ensures accuracy and avoids errors that may arise from mixing different units. One common approach is to convert all measurements to a standard unit, such as meters, before calculating distances.

function convertToMeters($value, $unit) {
    switch($unit) {
        case 'meters':
            return $value;
        case 'kilometers':
            return $value * 1000;
        case 'miles':
            return $value * 1609.34;
        // Add more conversion factors for other units as needed
        default:
            return null;
    }
}

// Example usage
$distanceInKilometers = 10;
$distanceInMeters = convertToMeters($distanceInKilometers, 'kilometers');
echo $distanceInMeters;