Scala之ListBuffer、ArrayBuffer、Queue及Stack介绍

1、代码

package com.yy.base

import scala.collection.immutable.Queue

object BufferQueueAndStackTest extends App {
//ListBuffer
import scala.collection.mutable.ListBuffer
val listBuffer = new ListBuffer[Int]
listBuffer += 1
listBuffer += 2
println(listBuffer)

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

//不可变Queue
val queue1 = Queue[Int]()
//进队：一个元素
val queue2 = queue1.enqueue(1)
//进队：一个List
val queue3 = queue2.enqueue(List(2,3,4,5,6))
println(queue3)
//拆分成两个部分
val (element,rest) = queue3.dequeue
println(element+":"+ rest)

//可变Queue
import scala.collection.mutable.Queue
val queue_ = Queue[String]()
queue_ += "a"
queue_ ++= List("b","c")
println(queue_)
//返回第一个元素
println(queue_.dequeue())
//打印剩余元素
println(queue_)

//Stack:FIFO
import scala.collection.mutable.Stack
val stack = new Stack[Int]
stack.push(1)
stack.push(2)
stack.push(3)
println(stack.pop())
println(stack)
println(stack.pop())
println(stack)
}2、结果
ListBuffer(1, 2)
ArrayBuffer(1, 2)
Queue(1, 2, 3, 4, 5, 6)
1:Queue(2, 3, 4, 5, 6)
Queue(a, b, c)
a
Queue(b, c)
3
Stack(2, 1)
2
Stack(1)