[英]Scala Hash Maps
我们如何从Scala的哈希图中选择一个随机键值对? 我有以下描述的地图
var map = scala.collection.mutable.Map[(Int,Int),ActorRef]()
val random = new Random();
var keys:List[Set(Int,Int)] = map.keySet;
var randomKey:(Int,Int) = keys.get( random.nextInt(keys.size()));
var value= map.get(randomKey);
val pair = map.toIndexedSeq(Random.nextInt(map.size))
这是一个编译并运行的示例:
import akka.actor.ActorRef
import scala.util.Random
import scala.collection.mutable.{Map => MutableMap}
object RandomMap {
def main(args: Array[String]): Unit = {
val map: MutableMap[(Int, Int), ActorRef] = MutableMap[(Int, Int), ActorRef]((9, 5) -> null, ((15, 1), null))
val random: Random = new Random()
val keys: List[(Int, Int)] = map.keySet.toList
val randomInt: Int = random.nextInt(keys.size)
val randomKey: (Int, Int) = keys(randomInt)
val value: Option[ActorRef] = map.get(randomKey)
println(s"Random key: $randomKey -> $value")
}
}
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