scala-单机wordcount

方法1：
val aa= List("Wade James Rose","Love Wade Cat James","Wade Scala Spark","James Scala Spark")
val aa1 = aa.flatMap(_.split(' '))
val aa2 = aa1.map((_,1))
val aa3 = aa2.groupBy(_._1)
val result = aa3.map(t=>(t._1,t._2.size)).toList.sortBy(_._2).reverse


方法2：
val bb=List("Wade James Rose","Love Wade Cat James","Wade Scala Spark","James Scala Spark").flatMap(_.split(' ')).map((_,1)).groupBy(_._1)
val bb1=bb.mapValues(_.foldLeft(0)(_+_._2))




val c=Array(1,2,3,4,5,6,7,8)
val c1=c.reduce(_+_)
val c2=c.fold(10)(_+_)