Question

The code is just for illustrative purposes, i.e. it is an example not a real code.

I tried this:

val results = for(i <- 1 to 20)
{
  val x = i+1
  println(x)
  yield x
}

and this

val results = for {i <- 1 to 20;
  val x = i+1;
  println(x)
}
  yield x

But none of this works — I need a generator, definition, and a statement — is this possible to do it with yield? If yes, what is the correct syntax?

Answer 1

Hopefully, this will get you started:

  val result = for (i <- 1 to 10 if i%2==0) yield {
     println(i); 
     i
  }

which is equivalent to

 (1 to 10).filter(_%2==0).map(x => { println(x); x } )