You can use loops instead of compex maps

For example:

Using this 'for' loop the 'yield' function acts like a flatmap:

  def loopMe() = {
    val numbers = for( i <- 1 to 10; if i % 2 == 0; 
                       j <- i to 10 if j % 2 == 1) yield i * j
    println(numbers)
  }

Here is the equivalent with traditional maps and filters:

  def mapMe() = {
    val num2 = (1 to 10).filter( a => a % 2 == 0)
    val num3 = num2.flatMap( a => (a to 10).filter(b => b % 2 == 1).map(c =>  c * a ) )

    println(num3)
  }

Funky stuff with for loops & prepopulating lists

You can pre populate a list with a loop like "val list = 1 to 20"

You can return stuff from a for loop with the "yield" command

def looping() = {
 val myList = (1 to 20 by 3)
 println(myList)

 val list2 = for( i <- myList if i % 2 == 0 ) yield i
 println(list2) 
} 

Dont think loop!

When ever you want to loop thru a list returning a new list of values use map or flatmap

If you do need to loop:
for( i <- 0 until 4) {
}