3. ArrayBuffer上的常用操作

添加一個或多個元素：

+=

添加集合：

++=

刪除一個或多個元素：

-=

刪除集合元素：

--=

插入元素： 第一個參數(shù)是下標，第二個參數(shù)是一個可變參數(shù)列表，支持同時插入多個值

(n:Int,ele:Int*)

刪除元素：可以直接指定下標，還可以同時指定下標和要刪除的元素個數(shù)

remove(n:Int)

remove(n:Int,count:Int)

清空集合：

clear

判空：

isEmpty

scala> ab

res8: scala.collection.mutable.ArrayBuffer[Int] = ArrayBuffer(1, 2, 3, 4, 5, 6)

scala> ab+=10

res9: ab.type = ArrayBuffer(1, 2, 3, 4, 5, 6, 10)

scala> ab+=(20,30)

res10: ab.type = ArrayBuffer(1, 2, 3, 4, 5, 6, 10, 20, 30)

scala> ab++=Array(5,6)

res11: ab.type = ArrayBuffer(1, 2, 3, 4, 5, 6, 10, 20, 30, 5, 6)

scala> ab-=1

res12: ab.type = ArrayBuffer(2, 3, 4, 5, 6, 10, 20, 30, 5, 6)

scala> ab-=(5,6)

res13: ab.type = ArrayBuffer(2, 3, 4, 10, 20, 30, 5, 6)

scala> ab--=Array(10,20,30)

res14: ab.type = ArrayBuffer(2, 3, 4, 5, 6)

scala> ab.(1,6,6,6)

scala> ab

res16: scala.collection.mutable.ArrayBuffer[Int] = ArrayBuffer(2, 6, 6, 6, 3, 4, 5, 6)

scala> ab.remove(3)

res17: Int = 6

scala> ab

res18: scala.collection.mutable.ArrayBuffer[Int] = ArrayBuffer(2, 6, 6, 3, 4, 5, 6)

scala> ab.remove(0,2)

scala> ab

res20: scala.collection.mutable.ArrayBuffer[Int] = ArrayBuffer(6, 3, 4, 5, 6)

scala> ab.isEmpty

res21: Boolean = false

scala> ab.clear

scala> ab.isEmpty

res23: Boolean = true