val g = List(1,2,3)
val k = g.fold((0,0))((a:Tuple2[Int,Int],b:Int)=>(a._1+b,a._2+1))
但是我收到以下错误信息 =
found : ((Int, Int), Int) => (Int, Int)
required: (Any, Any) => Any
g.fold((0,0))((a:Tuple2[Int,Int],b:Int)=>(a._1+b,a._2+1))
请问为什么它期望一个“任意”类型。
但以下内容有效:
g.map((_,1))
g.map((_,1)).fold((0,0))((a,b)=> (a._1+b._1,a._2+b._2))
res211: (Int, Int) = (6,3)