Brief Kotlin example #1

fun login(user: String, password: String) {
    if (user.isEmpty()) {
        println("Empty user not allowed.")
        return
    }

    if (password.isEmpty()) {
        println("Empty password not allowed.")
        return
    }

    println("User: ${user}")
    println("Password: ${password}")
}

fun main(args: Array<String>) {
    login("", "")
    login("my_user", "")
    login("my_user", "my_password")
}