foldLeft v. foldRight - does it matter?

Question

Previously, Nicolas Rinaudo answered my question on Scala\'s List foldRight Always Using foldLeft?

Studying Haskell currently, my understanding is that foldRig

Answer 1

scala> val words = List("Hic", "Est", "Index")
words: List[String] = List(Hic, Est, Index)

Incase of foldLeft: List elements will add to the empty string first and followed

words.foldLeft("")(_ + _) == (("" + "Hic") + "Est") + "Index"      //"HicEstIndex"

Incase of foldRight: Empty string will add to end of elements

words.foldRight("")(_ + _) == "Hic" + ("Est" + ("Index" + ""))     //"HicEstIndex"

Both cases will return the same output

def foldRight[B](z: B)(f: (A, B) => B): B
def foldLeft[B](z: B)(f: (B, A) => B): B