Type Extensions in Swift

// Extending existing types
extension Int {
    var isEven: Bool {
        return self % 2 == 0
    }

    func squared() -> Int {
        return self * self
    }
}

let number = 42
print(number.isEven)  // true
print(number.squared())  // 1764

// Extending with initializers
extension String {
    init(banner str: String, times count: Int) {
        self = String(repeating: str, count: count)
    }
}