val inRange1: (String) -> Boolean = { s: String -> s.startsWith("H") } val inRange2: (String) -> Boolean = { it.lowercase().endsWith("at") } fun filterIt2Long(vals: List<String>, func: (String) -> Boolean): List<String> { val list = mutableListOf<String>() for (v in vals) { if (func.invoke(v)) list.add(v) } return list } fun filterIt2Short(vals: List<String>, func: (String) -> Boolean): List<String> = vals.filter(func) fun main() { println(filterIt2Long(listOf("hi", "HA"), inRange1)) println(filterIt2Long(listOf("PAT", "at"), inRange2)) println(filterIt2Short(listOf("hi", "HA"), inRange1)) println(filterIt2Short(listOf("BAT", "HA"), inRange2)) println(filterIt2Short(listOf("BAT", "HA")) { s: String -> s.uppercase().endsWith("AT") }) println(filterIt2Short(listOf("BAT", "HA")) { it.lowercase().contains("a") }) println(filterIt2Short(listOf("BAT", "HA")) { it.capitalize().startsWith("B") }) }