scala：如何将ArrayBuffer转换为Set？

Question

我一直在寻找一些关于如何将ArrayBuffer转换为Set的时间，HashSet我想是准确的。任何提示？

Answer 1

ArrayBuffer

中实施了toSet个功能

示例：

scala> import collection.mutable.ArrayBuffer
import collection.mutable.ArrayBuffer

scala> import collection.immutable.HashSet
import collection.immutable.HashSet

scala> val a = new ArrayBuffer(2)
a: scala.collection.mutable.ArrayBuffer[Nothing] = ArrayBuffer()

scala> val b = a.toSet
b: scala.collection.immutable.Set[Nothing] = Set()

Answer 2

设置：

scala> val bf = ArrayBuffer(1,2,3,4)
bf: scala.collection.mutable.ArrayBuffer[Int] = ArrayBuffer(1, 2, 3, 4)
scala> bf.toSet
res0: scala.collection.immutable.Set[Int] = Set(1, 2, 3, 4)

到HashSet：

scala> val hs = new HashSet[Int]++ bf.toSet
hs: scala.collection.immutable.HashSet[Int] = Set(1, 2, 3, 4)

Answer 3

为了完整起见，还有一个方法：

scala> import collection.mutable.ArrayBuffer
import collection.mutable.ArrayBuffer

scala> val as = ArrayBuffer(34, 89, 11)
as: scala.collection.mutable.ArrayBuffer[Int] = ArrayBuffer(34, 89, 11)

scala> Set(as: _*)
res13: scala.collection.immutable.Set[Int] = Set(34, 89, 11)