Question

<Haskell>

Define an action adder :: IO () that reads a given number of integers from the keyboard, one per line, and displays their sum. For example: > adder

How many numbers? 5

1 3 5 7 9

The total is 25

Hint: start by defining an auxiliary function that takes the current total and how many numbers remain to be read as arguments. You will also likely need to use the library functions read and show.

Answer 1

Please find the haskell program and it output below:

adder                :: IO ()

adder               = do

                           x <- getLine

                           total <- getnums (read x :: Int)

                           putStrLn (" total of numbers is: " ++ show (sum total))

getnums              :: Int -> IO [Int]

getnums 0            = return []

getnums x            = do

                           ns <- getLine

                           let int = read ns :: Int

                           total <- getnums (x-1)

                           return (int:total)

In the output , 4 numbers are entered 3,2 ,4,5 and their sum is 14