map
val scoreMap = Map("leo" -> 90, "jack" -> 60, "tom" -> 70) val names = List("leo", "jack", "tom") names.map(scoreMap(_))
flatmap
val scoreMap = Map("leo" -> List(80, 90, 60), "jack" -> List(70, 90, 50), "tom" -> List(60,70,40)) names.map(scoreMap(_)) names.flatMap(scoreMap(_))
collect操作,结合偏函数使用
"abc".collect { case 'a' => 1; case 'b' => 2; case 'c' => 3 }
foreach操作,遍历
names.foreach(println _)
reduce
List(1, 2, 3, 4).reduceLeft(_ - _) List(1, 2, 3, 4).reduceRight(_ - _)
fold
List(1, 2, 3, 4).foldLeft(10)(_ - _) List(1, 2, 3, 4).foldRight(10)(_ - _)