Scala:类型不匹配

我花了大量的时间来解决以下问题：

rmseList是双打的列表

val rmseList = List(Double)

var tempRMSE : Double = 0.0;
for(rmse <- rmseList) {
  val idx = rmseList.indexOf(rmse) + 1
  tempRMSE = rmse
}

---

您可能已将

Double

的伴生对象放入列表中，而不是实际将Double放入其中。下面是一个例子：

scala> val xs = List(Double)
xs: List[Double.type] = List(object scala.Double)

scala> var d: Double = 0
d: Double = 0.0

scala> for (x <- xs) { d = x }
<console>:10: error: type mismatch;
 found   : Double.type
 required: Double
              for (x <- xs) { d = x }

scala>val xs=List（双精度）
xs:List[Double.type]=List（对象scala.Double）
scala>vard:Double=0
d:Double=0.0
scala>for（x）什么是
rmseList
？这实际上与
rmseList.last
不一样吗？这个循环在编写时毫无意义。
scala> val xs = List(Double)
xs: List[Double.type] = List(object scala.Double)

scala> var d: Double = 0
d: Double = 0.0

scala> for (x <- xs) { d = x }
<console>:10: error: type mismatch;
 found   : Double.type
 required: Double
              for (x <- xs) { d = x }