Type Checking & Casting in Swift

// Type checking with 'is'
let items: [Any] = [1, "hello", 3.14, true]

for item in items {
    if item is Int {
        print("Integer: \(item)")
    } else if item is String {
        print("String: \(item)")
    } else if item is Double {
        print("Double: \(item)")
    }
}

// Downcasting with as? and as!
class Animal {
    var name: String
    init(name: String) {
        self.name = name
    }
}

class Dog: Animal {
    func bark() {
        print("Woof!")
    }
}

class Cat: Animal {
    func meow() {
        print("Meow!")
    }
}

let animals: [Animal] = [Dog(name: "Rex"), Cat(name: "Whiskers")]

for animal in animals {
    if let dog = animal as? Dog {
        dog.bark()
    } else if let cat = animal as? Cat {
        cat.meow()
    }
}