String parsing thru lists

Filter numbers from strings.

   println( "there are 7 numbers 8 in 2 here"
            .toList.filter(Character.isDigit) )

Load the first word only.

   println(("first word only".toList.takeWhile(c => c != ' ') ).mkString)

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) 
} 

cool list functions

list functions:

list.zipWithIndex = (a,b,c) => (a=>1,b=>2,c=>3)
list.slice(start,end) = cuts out this part of the list
list.take(n) ::: list.drop(n) == list = get the first n elements append them to not the first n elements

Scala - Flatten lists & use asInstanceOf

 
  def flatten3(l: List[_]): List[_] = {
    l.flatMap(a => {
      if (a.isInstanceOf[List[_]]) flatten3(a.asInstanceOf[List[_]])
      else List(a)
    })
  }