Scala - Why a function returns Unit instead of an RDD?

Question

When I've implemented the function I wanted it to return an RDD. And probably collect it to List later. But why does it return Unit instead? What should I change in the implementation to make it return an RDD?

Sales is a map (saleId, Saletype) - val sales: Map[Int, String]

val processSales: Unit = sales.foreach(sale => sc.makeRDD(salesService.getData(sale._1)))

What is the type of `sales` object ? – philantrovert Jul 18 '18 at 07:54 — philantrovert, Jul 18 '18 at 07:54
why don't you iterate with `map` function over an RDD? – nomadSK25 Jul 18 '18 at 07:57 — nomadSK25, Jul 18 '18 at 07:57
It is a `Map[Int, String]`, sorry for missing this – samba Jul 18 '18 at 07:59 — samba, Jul 18 '18 at 07:59

score 3 · Answer 1 · answered Jul 18 '18 at 07:53

3

foreach returns Unit, You can see the return type as below

def foreach(f: T => Unit): Unit =

Use map instead to return an RDD

def map[U: ClassTag](f: T => U): RDD[U] =

answered Jul 18 '18 at 07:53

koiralo

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Scala - Why a function returns Unit instead of an RDD?

1 Answers1