// Created on savesnippets.com · https://savesnippets.com/rdnlz67IjVo3dX
class UserController {
    // Initialized later (by DI framework, Android lifecycle, etc.)
    lateinit var userService: UserService

    fun init(svc: UserService) {
        userService = svc
    }

    fun isReady(): Boolean = ::userService.isInitialized      // safe check

    fun doWork() {
        if (!isReady()) error("controller not initialized")
        // userService.greet(...)
    }
}

class UserService(val name: String)

fun main() {
    // repeat — for-loop without an index name
    repeat(5) { println("hello $it") }

    val c = UserController()
    println(c.isReady())                          // false
    c.init(UserService("alice"))
    println(c.isReady())                          // true

    // Accessing uninitialized lateinit throws UninitializedPropertyAccessException
}