Sync

Task/Copy-a-string/Scala/copy-a-string.scala

@@ -1,2 +1,13 @@
-val src = "Hello"
-val des = src
+  val src = "Hello"
+  // Its actually not a copy but a reference
+  // That is not a problem because String is immutable
+  // In fact its a feature
+  val des = src
+  assert(src eq des) // Proves the same reference is used.
+  // To make a real copy makes no sense.
+  // Actually its hard to make a copy, the compiler is too smart.
+  // mkString, toString makes also not a real copy
+  val cop = src.mkString.toString
+  assert((src eq cop))                 // Still no copyed image
+  val copy = src.reverse.reverse       // Finally double reverse makes a copy
+  assert(src == copy && !(src eq copy))// Prove, but it really makes no sense.