4、集合（接着上次的集合继续学习）4.4可变集合1、ListBuffervallistBuffer1:ListBuffer[Int]=newListBuffer[Int]println(s"$listBuffer1")listBuffer1.+=(11)listBuffer1.+=(22)listBuffer1.+=(33)listBuffer1.+=(11)listBuffer1.+=(55)listBuffer1.+=(22)listBuffe