fun main(args : Array<String>){ val text : String? = null //akses cek null if(text != null){ val textLength = text.length } //safe call text?.length //elvis Operator ?: val textLength = text?.length :? 7 //val textLength = if(text != null) text.length else 7 //non-null assertion (!!) tidak disarankan karena dapat mengakses null val textLength = text!!.length }