1、初始化定長(zhǎng)數(shù)組

    //通過顯示指定類型實(shí)例化一個(gè)數(shù)組
    val array01 = new Array[Int](3)
    array01(0)=6
    array01(1)=7
    array01(2)=8
    //通過隱式推斷來(lái)實(shí)例化一個(gè)數(shù)組
    val array02 = Array(1,2,3)

2、初始化變長(zhǎng)數(shù)組

對(duì)于長(zhǎng)度動(dòng)態(tài)變化的數(shù)組，java中是ArrayList, Scala中是ArrayBuffer

   import scala.collection.mutable.ArrayBuffer

    val arrayBuffer = new ArrayBuffer[Int]()
    //val arrayBuffer =  ArrayBuffer[Int]()  //也可以去掉new
    arrayBuffer += 11 //在尾端添加元素
    arrayBuffer += 12
    arrayBuffer +=(4,5,6) //在尾端添加多個(gè)元素
    arrayBuffer ++=Array(17,18,19) //++=追加任何集合

3、遍歷數(shù)組（定長(zhǎng)數(shù)組和緩沖數(shù)組抖音文案一樣的方法）

    for(i <- 0 until arrayBuffer.length ){
      println(arrayBuffer(i))
    }

    for(i <- 0 to arrayBuffer.length-1){
      println(arrayBuffer(i))
    }

    for(ele <- arrayBuffer){
      println(ele)
    }

utiI是Richlnt類的方法，返回所有小于但不包括上限的數(shù)字

4、顯示數(shù)組內(nèi)容

顯示數(shù)組或數(shù)組緩沖的內(nèi)容，可以用mkString方法，它允許你指定元素之間的分隔符。

    //顯示數(shù)組內(nèi)容
    val str01=array02.mkString("{",",","}")
    println(str01)
    val str02=array02.mkString(",")
    println(str02)
    val arrayBuffer_str01= arrayBuffer.mkString(",")
    println(arrayBuffer_str01)
    val arrayBuffer_str02= arrayBuffer.mkString("{",",","}")
    println(arrayBuffer_str02)

{1,2,3}
1,2,3
11,12,4,5,6,17,18,19
{11,12,4,5,6,17,18,19}

5、操作緩沖數(shù)組

    arrayBuffer.remove(0)
    arrayBuffer.insert(0,999)
    println(arrayBuffer.mkString(","))

    val array03=arrayBuffer.toArray //緩沖數(shù)組轉(zhuǎn)化為定長(zhǎng)數(shù)組
    println(array03.mkString(" "))

    val arrayBuffer01=array01.toBuffer   //定長(zhǎng)數(shù)組轉(zhuǎn)化為緩沖數(shù)組
    arrayBuffer01 +=(111,222)
    println(arrayBuffer01.mkString(" "))

999,12,4,5,6,17,18,19
999 12 4 5 6 17 18 19
6 7 8 111 222

6、數(shù)組轉(zhuǎn)化（for推導(dǎo)式和守衛(wèi)式）

推導(dǎo)式

    for(i <- arrayBuffer if i % 2==0){
      print(i+" ")
    }
    println()
    //等價(jià)于
    val arr=arrayBuffer.filter(_%2==0)
    for(ele <- arr){
      print(ele+" ")
    }

12 4 6 18 
12 4 6 18 

守衛(wèi)式

    val arr01=for(i <- array01) yield i*2
    for(ele <- arr01){
      print(ele+" ")
    }
    println()
    //等價(jià)于
    val arr02=array01.map(_*2)
    for(ele <- arr02){
      print(ele+" ")
    }

12 14 16 
12 14 16