Thursday, October 13, 2016

List methods : toArray, toList, copyToArray(), iterator

scala> // toArray, toList #354

scala> val data = List("a", "b", "c", "d", "e", "f")
data: List[String] = List(a, b, c, d, e, f)

scala> val arr = data.toArray
arr: Array[String] = Array(a, b, c, d, e, f)

scala> val lst = arr.toList
lst: List[String] = List(a, b, c, d, e, f)

scala>

scala> // copyToArray

scala> val arr = new Array[Int](7)
arr: Array[Int] = Array(0, 0, 0, 0, 0, 0, 0)

scala> arr.size
res18: Int = 7

scala> val lst = List(5, 6, 7)
lst: List[Int] = List(5, 6, 7)

scala> lst.copyToArray(arr, 3)

scala> arr
res20: Array[Int] = Array(0, 0, 0, 5, 6, 7, 0)

scala>

scala> // iterator

scala> val data = List("a", "b", "c", "d", "e", "f")
data: List[String] = List(a, b, c, d, e, f)

scala> val it = data.iterator
it: Iterator[String] = non-empty iterator

scala> it.next
res21: String = a

scala> it.next
res22: String = b