Added enum sample code in Scala 3

scala-core-modules/scala-core-oop/src/main/scala/com/baeldung/scala/enumerations/Fingers.scala

@@ -1,5 +1,7 @@
 package com.baeldung.scala.enumerations
 
+// This is Scala 2 based enumeration. It still works in Scala 3 for compatibility.
+// However, this might become unsupported in future release. In scala 3, use the keyword `enum`
 object Fingers extends Enumeration {
   type Finger = Value
 

scala-core-modules/scala-core-oop/src/main/scala/com/baeldung/scala/enumerations/scala3/Fingers.scala

@@ -0,0 +1,10 @@
+package com.baeldung.scala.enumerations.scala3
+
+enum Fingers(val height: Double) {
+  case Thumb extends Fingers(1)
+  case Index extends Fingers(4)
+  case Middle extends Fingers(4.1)
+  case Ring extends Fingers(3.2)
+  case Little extends Fingers(0.5)
+  def heightInCms(): Double = height * 2.54
+}

scala-core-modules/scala-core-oop/src/test/scala/com/baeldung/scala/enumerations/scala3/FingersUnitTest.scala

@@ -0,0 +1,20 @@
+package com.baeldung.scala.enumerations.scala3
+
+import org.junit.Test
+import org.junit.Assert.assertTrue
+
+class FingersUnitTest {
+
+  @Test
+  def givenAFinger_getTheHeight(): Unit = {
+    val Thumb = Fingers.Thumb
+    assertTrue(Thumb.height == 1d)
+  }
+
+  @Test
+  def givenAFinger_getTheHeightInCm(): Unit = {
+    val Thumb = Fingers.Thumb
+    assertTrue(Thumb.heightInCms() == 2.54d)
+  }
+
+}