Flitering methods in List : filter(), partition(), find(), takeWhile(), dropWhile(), span()

scala> // filter() #359

scala> val data = List(1, 2, 3, 4, 4, 5, 5, 6)
data: List[Int] = List(1, 2, 3, 4, 4, 5, 5, 6)

scala> val res = data.filter(_ < 4)
res: List[Int] = List(1, 2, 3)

scala>

scala> // partition()

scala> //  Returns pair of list

scala> val data = List(1, 2, 3, 4, 4, 5, 5, 6)
data: List[Int] = List(1, 2, 3, 4, 4, 5, 5, 6)

scala> val res = data.partition(_ < 4)
res: (List[Int], List[Int]) = (List(1, 2, 3),List(4, 4, 5, 5, 6))

scala>

scala> // find() : Returns Option...ie Some/None #360

scala> val data = List(1, 2, 3, 4, 4, 5, 5, 6)
data: List[Int] = List(1, 2, 3, 4, 4, 5, 5, 6)

scala> val res = data.find(_ > 3)
res: Option[Int] = Some(4)

scala>

scala> // takeWhile()

scala> val data = List(1, 2, 3, 4, 4, 5, 5, 6)
data: List[Int] = List(1, 2, 3, 4, 4, 5, 5, 6)

scala> val res = data.takeWhile(_ < 5)
res: List[Int] = List(1, 2, 3, 4, 4)

scala>

scala> // dropWhile()

scala> val data = List(1, 2, 3, 4, 4, 5, 5, 6)
data: List[Int] = List(1, 2, 3, 4, 4, 5, 5, 6)

scala> val res = data.dropWhile(_ < 5)
res: List[Int] = List(5, 5, 6)

scala>

scala> // span()

scala> val data = List(1, 2, 3, 4, 4, 5, 5, 6)
data: List[Int] = List(1, 2, 3, 4, 4, 5, 5, 6)

scala> val res = data.span(_ < 5)
res: (List[Int], List[Int]) = (List(1, 2, 3, 4, 4),List(5, 5, 6))