{"width":"100%","title":"\u3069\u3046\u66f8\u304f.org\u8ab2\u984c\u300c IPv4\u30a2\u30c9\u30ec\u30b9\u306e\u30de\u30b9\u30af\u306e\u5909\u63db \u300d","html":"<iframe src=\"https://hatenablog-parts.com/embed?url=https%3A%2F%2Fuehaj.hatenablog.com%2Fentry%2F20090808%2F1249699687\" title=\"\u3069\u3046\u66f8\u304f.org\u8ab2\u984c\u300c IPv4\u30a2\u30c9\u30ec\u30b9\u306e\u30de\u30b9\u30af\u306e\u5909\u63db \u300d - uehaj&#39;s blog \" class=\"embed-card embed-blogcard\" scrolling=\"no\" frameborder=\"0\" style=\"display: block; width: 100%; height: 190px; max-width: 500px; margin: 10px 0px;\"></iframe>","provider_name":"Hatena Blog","blog_title":"uehaj's blog ","version":"1.0","url":"https://uehaj.hatenablog.com/entry/20090808/1249699687","height":"190","blog_url":"https://uehaj.hatenablog.com/","type":"rich","image_url":null,"description":"IPv4\u30a2\u30c9\u30ec\u30b9\u306e\u30de\u30b9\u30af\u306e\u5909\u63db\u3082\u3084\u3063\u3066\u307f\u305f\u3002\u6295\u7a3f\u3057\u305f\u3042\u3068\u3067\u30b2\u30f3\u30be\u30a6\u3055\u3093\u306e\u3092\u898b\u308b\u3068\u3001\u300cInteger/Long.toBinaryString\u300d\u3068\u3044\u3046\u30e1\u30bd\u30c3\u30c9\u3084count\u3068\u3044\u3046\u30e1\u30bd\u30c3\u30c9\u3092\u4f7f\u3063\u3066\u305f\u306e\u3067\u3055\u3059\u304c\u3068\u601d\u3044\u307e\u3057\u305f\u3002\u4ee5\u4e0b\u306f\u305d\u308c\u3092\u53d6\u308a\u8fbc\u3093\u3060\u30d0\u30fc\u30b8\u30e7\u30f3\u3002 def netMask(addr) { Long.toString(addr.split(/\\./).inject(0){a,b->a*256+(b as long)},2).count('1') } assert netMask(\"255.255.255.0\")==24 assert netMask(\"255.255.255.128\")==25 \u2026","author_url":"https://blog.hatena.ne.jp/uehaj/","author_name":"uehaj","published":"2009-08-08 11:48:07","categories":["groovy"],"provider_url":"https://hatena.blog"}