The Difference {}, () in kotlin null check I'm practicing null checking in kotlin When I use Elvis operator ?: I use {} but the correct way is using (). But My mistake, the result was wrong. My Mistake Codes are below. var name: String = "eunno"//NonNull val lastName: String? = null val fullName = name + " " + {lastName ?: "No lastName"} Result when use {} eunno Function0 Result when use () eunno No lastName I don't understand the difference of results. Is there any difference about using {}, ()?