eclare(strict_types=1);
/**
* Immutable Data Transfer Object (DTO) to hold calculated circle metrics.
* Requires PHP 8.2+.
*/
readonly class CircleMetrics
{
public function __construct(
public float $diameter,
public float $circumference,
public float $area
) {}
}
/**
* Calculates the diameter, circumference, and area of a circle.
*
* @param float $radius The radius of the circle (must be non-negative).
* @return CircleMetrics An object containing the calculated metrics.
* @throws InvalidArgumentException If the radius is negative.
*/
function calculateCircleMetrics(float $radius): CircleMetrics
{
// Guard clause: radius cannot be negative
if ($radius < 0.0) {
throw new InvalidArgumentException('Radius cannot be negative.');
}
$diameter = 2.0 * $radius;
$circumference = 2.0 * M_PI * $radius;
// Standard multiplication ($radius * $radius) is more efficient than pow($radius, 2)
$area = M_PI * ($radius * $radius);
return new CircleMetrics($diameter, $circumference, $area);
}
// --- Example Usage ---
try {
$radius = 3.0;
// Retrieve calculated metrics
$metrics = calculateCircleMetrics($radius);
// Output results formatted to 2 decimal places using number_format
echo "Radius: {$radius}\n";
echo "Diameter: {$metrics->diameter}\n";
echo "Circumference: " . number_format($metrics->circumference, 2) . "\n";
echo "Area: " . number_format($metrics->area, 2) . "\n";
}
catch (InvalidArgumentException $e) {
echo "Error: " . $e->getMessage() . "\n";
}
/*
run:
Radius: 3
Diameter: 6
Circumference: 18.85
Area: 28.27
*/
