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scalamapreduceword-count

Scala - reduce function

How to use reduce function in Scala? Is there a built in function like that? I have implemented a program to find word count in scala.

object count {
    def main(args: Array[String]) {
        val fruits = List("apple", "apple", "orange", "apple", "mango", "orange")
        val word = fruits.flatMap(_.split("\n"))
        val Map = word.map(word => (word,1)).groupBy(_._1)
        val reduce = Map.map(word => (word._1,word._2.foldLeft(0)((sum,c) => sum+ c._2)))
        println(reduce)     }}

How to replace foldleft with reduce function?

Solution

  • Entire example above should be implemented like this 

    fruits groupBy(word => word) mapValues(_.size)

    or like this as replacement for fold

    val reduce = Map.map(word => (word._1,word._2.size))

    but if you absolutely positively must use reduce in the same exact code, it would be something like this

    val reduce = Map.map(word => (word._1,word._2.map(_=>1).reduce(_+_)))