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scala列表和集

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罗祥 2019-05-07 16:55:15 +08:00
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notes/Scala列表和集.md
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@ -441,6 +441,8 @@ res44: Boolean = true
上面介绍的List，由于其底层实现是链表，这意味着能快速访问List头部元素，但对尾部元素的访问则比较低效，这时候可以采用`ListBuffer`，ListBuffer提供了在常量时间内往头部和尾部追加元素。 上面介绍的List，由于其底层实现是链表，这意味着能快速访问List头部元素，但对尾部元素的访问则比较低效，这时候可以采用`ListBuffer`，ListBuffer提供了在常量时间内往头部和尾部追加元素。
```scala ```scala
import scala.collection.mutable.ListBuffer
object ScalaApp extends App { object ScalaApp extends App {
val buffer = new ListBuffer[Int] val buffer = new ListBuffer[Int]
@ -453,6 +455,8 @@ object ScalaApp extends App {
val list: List[Int] = buffer.toList val list: List[Int] = buffer.toList
println(list) println(list)
} }
//输出：List(3, 1, 2)
``` ```