How to correctly add a listener in android to kotlin?

Question

Android

decided to learn kotlin and android from head first android book and on page 301 the code of adding listener is not working

override fun onCreate(savedInstanceState: Bundle?) {
        super.onCreate(savedInstanceState)
        setContentView(R.layout.activity_main)
        val itemClickListener:AdapterView.OnItemClickListener = AdapterView.OnItemClickListener() {
            fun onItemClick(AdapterView<?> listView, itemView: View, position:Int, id: Long) {
                if(position == 0) {
                    val intent = Intent(MainActivity.this, DrinkCategoryActivity.class)
                            startActivity(intent)
                }
            }
        }

        val listView:ListView = findViewById<ListView>(R.id.list_options)
        listView.setOnClickListener(itemClickListener)
    }

need help to figure out what and how the
error occurs here itemClickListener:AdapterView

Answer 1

You have not declared an anonymous class.

val itemClickListener: AdapterView.OnItemClickListener = object : AdapterView.OnItemClickListener {
    override fun onItemClick(p0: AdapterView<*>?, p1: View?, p2: Int, p3: Long) {
        TODO("not implemented") 
    }       
}

or via lambda

val itemClickListener: AdapterView.OnItemClickListener = AdapterView.OnItemClickListener { p0, p1, p2, p3 ->
    TODO("not implemented") 
}

https://kotlinlang.ru/docs/reference/nested-class...