Scala学习笔记25【ListBuffer、ArrayBuffer、Queue、Stack常用操作实战】

package com.yl.scala

object Test {
def main(args: Array[String]){

//ListBuffer实战
import scala.collection.mutable.ListBuffer
val listBuffer = new ListBuffer[Int]
listBuffer += 1
listBuffer += 2
println("listBuffer = " + listBuffer) //listBuffer = ListBuffer(1, 2)

//ArrayBuffer实战
import scala.collection.mutable.ArrayBuffer
val arrayBuffer = new ArrayBuffer[Int]()
arrayBuffer += 1
arrayBuffer += 2
println("arrayBuffer = " + arrayBuffer) //arrayBuffer = ArrayBuffer(1, 2)

//Queue实战
import scala.collection.immutable.Queue  //immutable  不可变的
val empty = Queue[Int]()
val queue1 = empty.enqueue(1)
val queue2 = queue1.enqueue(List(1,2,3,4))
println("queue1 = " + queue1) //queue1 = Queue(1)
println("queue2 = " + queue2) //queue2 = Queue(1, 1, 2, 3, 4)

import scala.collection.mutable.Queue  //mutable   可变的
val queue = scala.collection.mutable.Queue[String]()
queue += "Scala"
queue ++= List("Hadoop", "Spark")
println("queue = " + queue)  //queue = Queue(Scala, Hadoop, Spark)
println(queue.dequeue()) //返回第一个元素  Scala

//Stack实战
import scala.collection.mutable.Stack
val stack = new Stack[String]()
stack.push("S")
stack.push("c")
stack.push("a")
stack.push("l")
stack.push("a")
println("stack = " + stack)  //stack = Stack(a, l, a, c, S)
println("stack.top = " + stack.top) //stack.top = a
println("stack.pop = " + stack.pop) //移除栈顶元素 stack.pop = a
println("stack.top = " + stack.top) //stack.top = l
}
}

listBuffer = ListBuffer(1, 2)
arrayBuffer = ArrayBuffer(1, 2)
queue1 = Queue(1)
queue2 = Queue(1, 1, 2, 3, 4)
queue = Queue(Scala, Hadoop, Spark)
Scala
stack = Stack(a, l, a, c, S)
stack.top = a
stack.pop = a
stack.top = l