Question

Scenario:
If there is an array of integers and I want to get array of integers in return that their total should not exceed 10.

I am a beginner in Haskell and tried below. If any one could correct me, would be greatly appreciated.

numbers :: [Int]
numbers = [1,2,3,4,5,6,7,8,9,10, 11, 12]

getUpTo :: [Int] -> Int -> [Int]
getUpTo (x:xs) max =
    if max <= 10
    then
            max = max + x
            getUpTo xs max
    else
            x

Input

getUpTo numbers 0

Output Expected

[1,2,3,4]

Answer 1

There is an answer with a fast version; however, I thought it might also be instructive to see the minimal change necessary to your code to make it work the way you expect.

numbers :: [Int]
numbers = [1,2,3,4,5,6,7,8,9,10, 11, 12]

getUpTo :: [Int] -> Int -> [Int]
getUpTo (x:xs) max =
    if max < 10 -- (<), not (<=)
    then
            -- return a list that still contains x;
            -- can't reassign to max, but can send a
            -- different value on to the next
            -- iteration of getUpTo
            x : getUpTo xs (max + x)
    else
            [] -- don't want to return any more values here