number_strings = (1..10).to_a.map{|n| n.to_s } p number_strings #=> ["1", "2", "3", "4", "5", "6", "7", "8", "9", "10"] number_strings = [] [*1..10].each{|n| number_strings << n } p number_strings #=> ["1", "2", "3", "4", "5", "6", "7", "8", "9", "10"] とかやってませんか? 配列を作ってすぐにmapとかeachとかselectするような場合、同じメソッドがRangeにもあるので、to_aは要らない。 「ArrayとRangeの両方にあるメソッド」は次のような式を実行することで列挙できる。 p ((1..10).to_a.methods & (
![そのto_a、必要? - Qiita](https://cdn-ak-scissors.b.st-hatena.com/image/square/00bdc95988696a979d727daea16e8871375f2232/height=288;version=1;width=512/https%3A%2F%2Fqiita-user-contents.imgix.net%2Fhttps%253A%252F%252Fcdn.qiita.com%252Fassets%252Fpublic%252Farticle-ogp-background-9f5428127621718a910c8b63951390ad.png%3Fixlib%3Drb-4.0.0%26w%3D1200%26mark64%3DaHR0cHM6Ly9xaWl0YS11c2VyLWNvbnRlbnRzLmltZ2l4Lm5ldC9-dGV4dD9peGxpYj1yYi00LjAuMCZ3PTkxNiZoPTMzNiZ0eHQ9JUUzJTgxJTlEJUUzJTgxJUFFdG9fYSVFMyU4MCU4MSVFNSVCRiU4NSVFOCVBNiU4MSUzRiZ0eHQtY29sb3I9JTIzMjEyMTIxJnR4dC1mb250PUhpcmFnaW5vJTIwU2FucyUyMFc2JnR4dC1zaXplPTU2JnR4dC1jbGlwPWVsbGlwc2lzJnR4dC1hbGlnbj1sZWZ0JTJDdG9wJnM9ZDk1MjVmMDRlZTI4NDU5YWE2ODQ0NjQ2YmRjNWE0ODc%26mark-x%3D142%26mark-y%3D112%26blend64%3DaHR0cHM6Ly9xaWl0YS11c2VyLWNvbnRlbnRzLmltZ2l4Lm5ldC9-dGV4dD9peGxpYj1yYi00LjAuMCZ3PTYxNiZ0eHQ9JTQwdGFkc2FuJnR4dC1jb2xvcj0lMjMyMTIxMjEmdHh0LWZvbnQ9SGlyYWdpbm8lMjBTYW5zJTIwVzYmdHh0LXNpemU9MzYmdHh0LWFsaWduPWxlZnQlMkN0b3Amcz1jYWU5ZDMxN2UyZDIzZjAwMTUxODBiMzZiNThjZmIyOQ%26blend-x%3D142%26blend-y%3D491%26blend-mode%3Dnormal%26s%3Dd1abcff78b5005bb84fd2ac28d641a28)