Functional Swift: Filter Function: Filter a given array of integers and output only those values that are less than a specified value

https://www.hackerrank.com/challenges/fp-filter-array/problem

import Foundation

func filterList(_ upperLimit: Int, _ list: [Int]) -> [Int] {
   if list.count <= 0 {
        return []
   }

   let element = list.first!
   let newList = Array(list.dropFirst(1))

   if element < upperLimit {
      return [element] + filterList(upperLimit, newList)
   }
   return filterList(upperLimit, newList)
}

print(filterList(3, [1, 2, 3, 4]))