Scala List

原创转载请注明出处：http://agilestyle.iteye.com/blog/2331949

ScalaList.scala

package org.fool.scala.basic

object ScalaList {
  def main(args: Array[String]): Unit = {
    val list1 = List(1, 2, 3)
    println(list1)

    val list2 = List("Hello", "World")
    println(list2)

    // List has a method named `:::' for list concatenation
    val list = list1 ::: list2
    println(list)

    // Perhaps the most common operator you'll use with lists is `::', which is pronounced "cons."
    // Cons prepends a new element to the beginning of an existing list and returns the resulting list.
    val twoThree = List(2, 3)
    val oneTwoThree = 1 :: twoThree
    println(oneTwoThree)

    val oneTwoThreeFour = 1 :: 2 :: 3 :: 4 :: Nil
    println(oneTwoThreeFour)

    val thrill = "I" :: "Love" :: "Scala" :: Nil
    // List(I, Love, Scala)
    println(thrill)
    // Scala
    println(thrill(2))
    // 1
    println(thrill.count(s => s.length == 4))
    // List(Scala)
    println(thrill.drop(2))
    // List(I)
    println(thrill.dropRight(2))
    // true
    println(thrill.exists(s => s == "Scala"))
    // false
    println(thrill.exists(s => s == "Spark"))
    // List(Love)
    println(thrill.filter(s => s.length == 4))
    // List(I, Scala)
    println(thrill.filterNot(s => s.length == 4))
    // false
    println(thrill.forall(s => s.endsWith("a")))

    println(thrill.foreach(s => print(s)))
    println(thrill.foreach(print))

    // I
    println(thrill.head)
    // Scala
    println(thrill.last)
    // List(I, Love)
    println(thrill.init)
    // List(Love, Scala)
    println(thrill.tail)
    // false
    println(thrill.isEmpty)
    // 3
    println(thrill.length)
    // List(Iy, Lovey, Scalay)
    println(thrill.map(s => s + 'y'))
    // I,Love,Scala
    println(thrill.mkString(","))
    // List(Scala, Love, I)
    println(thrill.reverse)
    // List(Scala, Love, I)
    println(thrill.sortWith((s, t) => s.charAt(0).toLower > t.charAt(0).toLower))
  }
}

Console Output

List(1, 2, 3)
List(Hello, World)
List(1, 2, 3, Hello, World)
List(1, 2, 3)
List(1, 2, 3, 4)
List(I, Love, Scala)
Scala
1
List(Scala)
List(I)
true
false
List(Love)
List(I, Scala)
false
ILoveScala()
ILoveScala()
I
Scala
List(I, Love)
List(Love, Scala)
false
3
List(Iy, Lovey, Scalay)
I,Love,Scala
List(Scala, Love, I)
List(Scala, Love, I)