Scala: Can there be any reason to prefer `filter+map` over `collect`?

Question

Can there be any reason to prefer filter+map:

list.filter (i => aCondition(i)).map(i => fun(i))

over collect?

Answer 1

One case where filter/map looks cleaner is when you want to flatten the result of filter

def getList(x: Int) = {
  List.range(x, 0, -1)
}

val xs = List(1,2,3,4)

//Using filter and flatMap
xs.filter(_ % 2 == 0).flatMap(getList)

//Using collect and flatten
xs.collect{ case x if x % 2 == 0 => getList(x)}.flatten