object Test {
def main(args: Array[String]): Unit = {
val bigData = List("Hadoop", "Spark")
val data = List(1, 2, 3)
val bigData_Core = "Hadoop" :: ("Spark" :: Nil)
val data_Int = 1 :: 2 :: 3 :: Nil //Nil:空,无
println(data.isEmpty)
println(data.head)
println(data.tail.head) //tail是除了haead之外的,这里返回2
val List(a, b) = bigData
println("a : " + a + " === " + " b: " + b)
val x :: y :: rest = data //打印rest为List(3)
//val x :: y :: rest :: Nil = data //打印rest为3
println("x: " + x + " === " + " y: " + y + " === " + rest)
val shuffledData = List(6, 3, 5, 6, 2, 9, 1)
println(sortList(shuffledData))
def sortList(list: List[Int]): List[Int] = list match {
case List() => List()
case head :: tail => compute(head, sortList(tail))
}
def compute(data: Int, dataSet: List[Int]): List[Int] = dataSet match {
case List() => List(data)
case head :: tail => if (data <= head) data :: dataSet
else head :: compute(data, tail)
}
}
}