如何检查变量是否是 scala 中的列表：Any is list?

Question

如何在 scala 中检查变量是否为列表：Any is list?

我需要类似

的东西

def isList(variable: Any): Boolean = {
  // code here for returning true or false
}

Answer 1

scala> def isList(v: Any) : Boolean = v match {
           case _: List[_] => true
           case _ => false
       }
isList: (v: Any)Boolean

scala> isList(List(1))
res0: Boolean = true

scala> isList(Array(1))
res1: Boolean = false

Answer 2

你可以简单地使用isInstanceOf方法


 def isList(variable: Any): Boolean =  variable.isInstanceOf[List[_]]
                                                  //> isList: (variable: Any)Boolean
  isList(List(1,2))                               //> res0: Boolean = true
  isList(1)                                       //> res1: Boolean = false
  isList(Array(1,2))                              //> res2: Boolean = false
</pre>

如何检查变量是否是 scala 中的列表：Any is list?

How to check if a variable is a list in scala: Any is list?

scala