Serena

import Foundation // Main entry point func main() { let calculator = Calculator() let result = calculator.add(5, 3) print("Result: \(result)") let user = User(name: "Alice", age: 30) user.greet() let area = Utils.calculateArea(radius: 5.0) print("Circle area: \(area)") } class Calculator { func add(_ a: Int, _ b: Int) -> Int { return a + b } func multiply(_ a: Int, _ b: Int) -> Int { return a * b } } struct User { let name: String let age: Int func greet() { print("Hello, my name is \(name) and I am \(age) years old.") } func isAdult() -> Bool { return age >= 18 } } enum Status { case active case inactive case pending } protocol Drawable { func draw() } class Circle: Drawable { let radius: Double init(radius: Double) { self.radius = radius } func draw() { print("Drawing a circle with radius \(radius)") } } // Call main main()