| fun f(s: String?, t: String): String { | |
| return s.plus(t) | |
| } | |
| fun g(s: String, t: Any?): String { | |
| return "$s$t" | |
| } | |
| fun h(s: String, t: Any?): String { | |
| return s + t | |
| } | |
| fun box(): String { | |
| if (f("O", "K") != "OK") return "Fail 1" | |
| if (g("O", "K") != "OK") return "Fail 2" | |
| if (h("O", "K") != "OK") return "Fail 3" | |
| return "OK" | |
| } |