How to use Scala to realize worldcount function

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Create a new ScalaWorldCount object:

Package com.ruozedata.day4

Object ScalaWorldCount {

Def main (args: Array [String]): Unit = {

Val lines = List ("hello ruoze hello jepson", "hello ruoze hello jepson hello china")

/ * * the first method

* flatMap=map+flatten lines.flatMap flattens data

* flatMap (_ .split ("")) takes each element (string) and cuts it according to the space

* map ((_, 1)) put the word occurrence once and 1 together (into tuples)

* the first _ of groupBy (_. _ 1) represents each tuple in List. A certain element in the tuple is taken with. _ n, that is, grouped according to an element in the tuple, and a map is returned.

The first _ gets a dual tuple and fetches the first tuple in the tuple. * map (t = > (t = > (t = 1). _. _ 2.size is the number of the second dual tuple.

*

, /

Val wc = lines.flatMap (_ .split (")). Map ((_, 1)). GroupBy (_. _ 1) .map (t = > (t = > (t.split _ 1 ~ 2.size)). ToList / / .sortBy (_. _ 2). Reverse

For (j)