Fold is incredibly important. You should learn it. https://en.wikipedia.org/wiki/Fold_(higher-order_function)

In Scala, the debate between using fold on an Option or using map and getOrElse is almost as old as the language. The method signature for this is:

  def fold[B](ifEmpty: => B)(f: (A) => B): B

That is to say, fold always returns type B, and takes two arguments. The first takes a function returning type B if the option is "empty" (None) and the second takes a function that is called with the contents of the Some. As you can see, it's syntactic sugar for map and getOrElse.

  def map[B](f: (A) => B): B

  def getOrElse[B](f: => B): B