kos31de https://blog.hatena.ne.jp/kos31de/ kos31de.txt https://kos31de.hatenadiary.jp/ 技術メモ 配列の中で条件に合致するものを取ってきてくれるのが、select 配列の各要素が条件に合致するかどうか、真偽値を返すのが、map irb(main):004:0> ["1", "2"].select {|i| i == "1"} => ["1"] irb(main):006:0> ["1", "2"].map {|i| i == "1"} => [true, false] selectの反対はreject irb(main):005:0> ["1", "2"].reject {|i| i == "1"} => ["2"] 190 <iframe src="https://hatenablog-parts.com/embed?url=https%3A%2F%2Fkos31de.hatenadiary.jp%2Fentry%2F2019%2F10%2F25%2F195934" title="selectとmap - kos31de.txt" class="embed-card embed-blogcard" scrolling="no" frameborder="0" style="display: block; width: 100%; height: 190px; max-width: 500px; margin: 10px 0px;"></iframe> Hatena Blog https://hatena.blog 2019-10-25 19:59:34 rich https://kos31de.hatenadiary.jp/entry/2019/10/25/195934 1.0 100%