{"description":"Ruby \u914d\u5217\u306e\u5909\u63db\u30fb\u96c6\u8a08\uff1amap\u30fbinject\u30fbflat_map \u306e\u4f7f\u3044\u65b9 \u914d\u5217\u3092\u5225\u306e\u5f62\u306b\u5909\u63db\u3057\u305f\u308a\u3001\u5408\u8a08\u30fb\u30b0\u30eb\u30fc\u30d7\u5316\u3057\u305f\u308a\u3059\u308b\u306b\u306f map\u30fbinject\u30fbflat_map \u3092\u4f7f\u3044\u307e\u3059\u3002 \u65e9\u308f\u304b\u308a\u307e\u3068\u3081 \u30e1\u30bd\u30c3\u30c9 \u623b\u308a\u5024 \u5411\u3044\u3066\u3044\u308b\u7528\u9014 map / collect \u914d\u5217 \u5404\u8981\u7d20\u3092\u5909\u63db\u3057\u305f\u65b0\u3057\u3044\u914d\u5217\u3092\u4f5c\u308b inject / reduce \u4efb\u610f\u306e\u5024 \u914d\u5217\u30921\u3064\u306e\u5024\u306b\u96c6\u8a08\u3059\u308b flat_map \u914d\u5217 \u5909\u63db\u3057\u306a\u304c\u30891\u968e\u5c64\u30d5\u30e9\u30c3\u30c8\u5316\u3059\u308b flatten \u914d\u5217 \u30cd\u30b9\u30c8\u3057\u305f\u914d\u5217\u3092\u5e73\u5766\u306b\u3059\u308b group_by \u30cf\u30c3\u30b7\u30e5 \u6761\u4ef6\u3067\u30b0\u30eb\u30fc\u30d7\u5316\u3059\u308b tally \u30cf\u30c3\u30b7\u30e5 \u8981\u7d20\u306e\u51fa\u73fe\u56de\u6570\u3092\u6570\u3048\u308b sum \u6570\u5024 \u5408\u8a08\u3092\u2026","image_url":null,"type":"rich","blog_url":"https://tech.fun-toy-life.com/","author_name":"plarail_hangout","height":"190","version":"1.0","provider_name":"Hatena Blog","categories":["Ruby"],"author_url":"https://blog.hatena.ne.jp/plarail_hangout/","title":"Ruby \u914d\u5217\u306e\u5909\u63db\u30fb\u96c6\u8a08\uff1amap\u30fbinject\u30fbflat_map \u306e\u4f7f\u3044\u65b9","html":"<iframe src=\"https://hatenablog-parts.com/embed?url=https%3A%2F%2Ftech.fun-toy-life.com%2Fentry%2F2026%2F06%2F30%2F215323\" title=\"Ruby \u914d\u5217\u306e\u5909\u63db\u30fb\u96c6\u8a08\uff1amap\u30fbinject\u30fbflat_map \u306e\u4f7f\u3044\u65b9 - Engineering Tech Dojo\" class=\"embed-card embed-blogcard\" scrolling=\"no\" frameborder=\"0\" style=\"display: block; width: 100%; height: 190px; max-width: 500px; margin: 10px 0px;\"></iframe>","blog_title":"Engineering Tech Dojo","url":"https://tech.fun-toy-life.com/entry/2026/06/30/215323","published":"2026-06-30 21:53:23","provider_url":"https://hatena.blog","width":"100%"}