{"blog_url":"https://blog.emattsan.org/","provider_url":"https://hatena.blog","categories":["Haskell","Ruby","Iolanguage","Csharp"],"author_url":"https://blog.hatena.ne.jp/E_Mattsan/","published":"2013-09-29 17:47:28","url":"https://blog.emattsan.org/entry/20130929/1380444448","provider_name":"Hatena Blog","image_url":null,"html":"<iframe src=\"https://hatenablog-parts.com/embed?url=https%3A%2F%2Fblog.emattsan.org%2Fentry%2F20130929%2F1380444448\" title=\" Filtering, then Mapping - \u30a8\u30f3\u30b8\u30cb\u30a2\u306e\u30bd\u30d5\u30c8\u30a6\u30a7\u30a2\u7684\u611b\u60c5\" class=\"embed-card embed-blogcard\" scrolling=\"no\" frameborder=\"0\" style=\"display: block; width: 100%; height: 190px; max-width: 500px; margin: 10px 0px;\"></iframe>","version":"1.0","blog_title":"\u30a8\u30f3\u30b8\u30cb\u30a2\u306e\u30bd\u30d5\u30c8\u30a6\u30a7\u30a2\u7684\u611b\u60c5","height":"190","description":"Haskell evenTen = map (\\n -> n * 10) . filter even Prelude> evenTen [1,2,3,4,5,6,7,8,9,10] [20,40,60,80,100] Ruby def evenTen(a) a.select{|n| n % 2 == 0}.map{|n| n * 10} end irb(main):004:0> evenTen [1,2,3,4,5,6,7,8,9,10] => [20, 40, 60, 80, 100] IO evenTen := method(n, n select(% 2 == 0) map(*10))I\u2026","width":"100%","title":" Filtering, then Mapping","type":"rich","author_name":"E_Mattsan"}