# 99 questions/Solutions/4

### From HaskellWiki

< 99 questions | Solutions(Difference between revisions)

Line 8: | Line 8: | ||

<haskell> | <haskell> | ||

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

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

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

This is <hask>length</hask> in <hask>Prelude</hask>. | This is <hask>length</hask> in <hask>Prelude</hask>. |

## 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