可变数组

1.添加

2.删除

3.修改

4.判断是否存在

Scala
object scala04 {
  def main(args: Array[String]):Unit = {
    val arr1 = scala.collection.mutable.ArrayBuilder(1,2,3)

    arr1 += 4

    arr1 += (5,6,7)

    arr1 -= 4

    arr1.removw(0,3)

    arr1(2) = 700
    println( arr1.comtains(6)) //第一元素
    println( arr1.comtains(8))
  }
}

1.排序

2.切片

3.过滤

4.搜索位置：检查某个元素的下标

object scala04 {
  def main(args: Array[String]):Unit = {
   val arr1 = scala.collection.mutable.ArrayBuilder(1,2,0,-1,20,3)
    
    val arr2 = arr1.sortWith((a,b)=>a>b)
    
    val arr3 = arr1.slice(0,3)
    
    val arr4 = arr1.filter(x => x>0)
    
    val target = -2
    val result = arr1.index0f(target)
    
    println(s"${target}的下标是 ${result}")
    
    arr4.foreach(ele=> println(ele))
  }
}