Problem 02

src/main/scala/ninetyNineScalaProblems/Problem02.scala

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+package ninetyNineScalaProblems
+
+object Problem02:
+    def lastButOneElement(list: List[Any]): Option[Any] =
+        list match
+            case l if l.length >= 2 => Some(list(l.length - 2))
+            case _ => None
+
+object Problem02Stdlib:
+    def lastButOneElement(list: List[Any]): Option[Any] =
+        list.reverse match
+            case last :: lastButOne :: tail => Some(lastButOne)
+            case _ => None

src/test/scala/ninetyNineScalaProblems/Problem02Suite.scala

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+package ninetyNineScalaProblems
+
+class Problem02Suite extends munit.FunSuite:
+    List(
+        (List(1, 2, 3, 4, 5), Some(4)),
+        (List(1, 2), Some(1)),
+        (List(1), None),
+        (List(), None)
+    ).foreach:
+        case (list, expected) =>
+            test(s"lastButOneElement returns [$expected]"):
+                assertEquals(Problem02.lastButOneElement(list), expected, "Problem02")
+                assertEquals(Problem02Stdlib.lastButOneElement(list), expected, "Problem02Stdlib")