# 99 questions/Solutions/4

### From HaskellWiki

< 99 questions | Solutions(Difference between revisions)

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<haskell> |
<haskell> |
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myLength' xs = snd $ last $ zip xs [1..] -- Just for fun |
myLength' xs = snd $ last $ zip xs [1..] -- Just for fun |
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+ | </haskell> |
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+ | |||

+ | <haskell> |
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+ | myLength = sum . map (\x -> 1) |
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</haskell> |
</haskell> |
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## Revision as of 15:02, 25 October 2011

(*) Find the number of elements of a list.

myLength :: [a] -> Int myLength [] = 0 myLength (_:xs) = 1 + myLength xs

myLength' = foldl (\n _ -> n + 1) 0 myLength'' = foldr (\_ n -> n + 1) 0 myLength''' = foldr (\_ -> (+1)) 0 myLength'''' = foldr ((+) . (const 1)) 0

myLength' xs = snd $ last $ zip xs [1..] -- Just for fun

myLength = sum . map (\x -> 1)

length

Prelude