Scala Option Cheatsheet

// flatMap
// This code is equivalent to:
// option.flatMap(foo(_))
option match {
 case None => None
 case Some(x) => foo(x)
}

// flatten
// This code is equivalent to:
// option.flatten
option match {
 case None => None
 case Some(x) => x
}

// map
// This code is equivalent to:
// option.map(foo(_))
option match {
 case None => None
 case Some(x) => Some(foo(x))
}

// foreach
// This code is equivalent to:
// option.foreach(foo(_))
option match {
 case None => {}
 case Some(x) => foo(x)
}

// isDefined
// This code is equivalent to:
// option.isDefined
option match {
 case None => false
 case Some(_) => true
}

// isEmpty
// This code is equivalent to:
// option.isEmpty
option match {
 case None => true
 case Some(_) => false
}


// forall
// This code is equivalent to:
// option.forall(foo(_))
option match {
 case None => true
 case Some(x) => foo(x)
}

// exists
// This code is equivalent to:
// option.exists(foo(_))
option match {
 case None => false
 case Some(x) => foo(x)
}

// orElse
// This code is equivalent to:
// option.OrElse(foo)
option match {
 case None => foo
 case Some(x) => Some(x)
}

// getOrElse
// This code is equivalent to:
// option.getOrElse(foo)
option match {
 case None => foo
 case Some(x) => x
}

// toList
// This code is equivalent to:
// option.toList
option match {
 case None => Nil
 case Some(x) => x :: Nil
}

Related protips

Have a fresh tip? Share with Coderwall community!