Scala if else assignment operator with enum is failing

Question

I have the following Scala code:

// RunMode.scala
object RunMode extends Enumeration {
  val CLIENT_MODE = Value("CLIENT")
  val SERVER_MODE = Value("SERVER")
}

// Driver.scala
object MyApp extends App {
  // Don't worry about this too much, the point is we get a valid
  // instance of RunMode to work with
  val runMode : RunMode = getRunMode(args)

  val qualifier : String = if runMode.eq(RunMode.CLIENT_MODE) "whistle" else "feather"

  // rest of main omitted for brevity
}

When this runs I get the following compiler error on the ternary operator:

/Users/myuser/myapp/src/main/com/me/myapp/Driver.scala:22: '(' expected but identifier found.
  val qualifier : String = if runMode.eq(RunMode.CLIENT_MODE) "whistle" else "feather"

Obviously the desired behavior could be rewritten as:

var qualifier : String = null
if(runMode.eq(RunMode.CLIENT_MODE)) {
  qualifier = "whistle"
} else {
  qualifier = "feather"
}

But why am I getting this error? What's the fix?

Answer 1

There is no ternary operator in Scala. Use if-else :

val qualifier : String = if (runMode eq RunMode.CLIENT_MODE) "whistle" else "feather"