Question

Haskell Programming 2. Returns the plural of a word by adding "s' unless the word ends in "y", in which can you remove the "y" and add "ies" 3. Write a function that takes two lists and returns a list of only those elements that appear in both lists. 4. Write a function that takes a list and an element and returns the number of times the element appears in the list. 5. Remove the leading spaces from a string without using trim or strip 6. Remove the trailing spaces from a string without using trim or strip 7. Remove both the leading and trailing spaces from a string without using trim or strip. (Using your functions from the previous question will make this casier.) 8. Given a list of integers and a number, remove all elements from the list that are evenly divisible by the number. You will probably want to use the mod function.

Answer 1

2)
import Data.List
convertPlural :: String -> String --function declaration
convertPlural word =
if isSuffixOf "y" word
then (init word) ++ "ies"
else word ++ "s"

3)
commonElem :: [String] -> [String] -> [String]
commonElem l1 l2 = l1 >>= (\s -> if s `elem` l2 then [s] else [])

4)
countFound :: String -> [String] -> Int
countFound s sList = (length . filter (== s)) sList

5)

import Data.Char
rmLeadSp :: String -> String
rmLeadSp s = dropWhile (not . isAlpha) s