flatmap map

flatmapmap.scala

val n : Option[Int] = None                      //> n  : Option[Int] = None
val ol = List(Option(1), n , Option(3), Option(5), n) //> ol  : List[Option[Int]] = List(Some(1), None, Some(3), Some(5), None)
  
ol map ( i => i map (j => j * 2))               //> res3: List[Option[Int]] = List(Some(2), None, Some(6), Some(10), None)

// FlatMap with map and same using For comprehension
ol flatMap ( i => i map (j => Option(j * 2)))   //> res5: List[Option[Int]] = List(Some(2), Some(6), Some(10))
for(o <- ol; i <- o) yield Option(i*2)          //> res6: List[Option[Int]] = List(Some(2), Some(6), Some(10))