# 99 questions/Solutions/4

### From HaskellWiki

< 99 questions | Solutions(Difference between revisions)

Line 8: | Line 8: | ||

<haskell> |
<haskell> |
||

− | myLength' :: [a] -> Int |
+ | myLength' = foldr (\_ n -> n + 1) 0 |

− | myLength' = foldr (\x n -> n + 1) 0 |
+ | myLength'' = foldr (\n _ -> n + 1) 0 |

</haskell> |
</haskell> |
||

## Revision as of 07:21, 17 November 2010

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

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

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

length

Prelude