scala3 feature examples - explicit nulls / published by https://github.com/dacr/code-examples-manager #d63219ff-c8cf-46f3-a927-d311db37ab35/dbc7531b140f994b388d4449b8fc56c1844030b3

scala3-feature-explicit-nulls.scala

// summary : scala3 feature examples - explicit nulls
// keywords : scala3, tutorial
// publish : gist
// authors : David Crosson
// license : Apache NON-AI License Version 2.0 (https://raw.githubusercontent.com/non-ai-licenses/non-ai-licenses/main/NON-AI-APACHE2)
// id : d63219ff-c8cf-46f3-a927-d311db37ab35
// created-on : 2021-04-21T11:45:13+02:00
// managed-by : https://github.com/dacr/code-examples-manager
// run-with : scala-cli  $file
//// run-with : scala-cli --scalac-option -Yexplicit-nulls $file

//> using scala  "3.1.1"
// using options -Yexplicit-nulls

@main def go():Unit = {
  val nullableResult : String | Null = java.lang.System.getenv("PATH")
  if (nullableResult != null) {
    val result: String = nullableResult // safe because of the previous test :)
    println(result)
  }
  val aresult:String = nullableResult // FAIL when the explicit feature is enabled (-Yexplicit-nulls)
  println(aresult)
}