{"url":"https://susisu.hatenablog.com/entry/2015/05/03/225746","height":"190","version":"1.0","width":"100%","blog_url":"https://susisu.hatenablog.com/","title":"Object.create(null)","provider_name":"Hatena Blog","categories":["JavaScript","\u30d7\u30ed\u30b0\u30e9\u30df\u30f3\u30b0"],"provider_url":"https://hatena.blog","author_name":"susisu","description":"\u4efb\u610f\u306e\u5165\u529b\u6587\u5b57\u5217\u306b\u5bfe\u3057\u3066\u5024\u3092\u7ba1\u7406\u3057\u305f\u3044\u3068\u304d, Object.create(null) \u304c\u4f7f\u3048\u308b. var obj = Object.create(null); console.log(obj[\"toString\"]); // => undefined \u3053\u3046\u3059\u308b\u3068 Object.prototype \u306b\u5b58\u5728\u3059\u308b\u30d7\u30ed\u30d1\u30c6\u30a3/\u30e1\u30bd\u30c3\u30c9\u3092\u7d99\u627f\u3057\u306a\u3044\u771f\u306b\u7a7a\u306e\u30aa\u30d6\u30b8\u30a7\u30af\u30c8\u304c\u4f5c\u6210\u3067\u304d\u308b\u306e\u3067, \u4f8b\u3048\u3070\u3046\u3063\u304b\u308a \"toString\" \u306a\u3069\u304c\u5165\u529b\u3055\u308c\u3066\u3082\u554f\u984c\u306a\u3044. \u3068\u3053\u308d\u3067 ES6 \u306b\u306f Map \u304c\u3042\u308b *1 \u304b\u3089\u305d\u308c\u3092\u4f7f\u3048\u3088, \u3068\u601d\u308f\u308c\u308b\u304b\u3082\u3057\u308c\u306a\u3044\u3051\u308c\u3069, \u8907\u88fd\u304c\u30b3\u30b9\u30c8\u306b\u306a\u308b\u5834\u5408\u3084, \u3042\u308b\u3044\u306f\u4e0a\u66f8\u304d\u3055\u308c\u306a\u3044\u9650\u308a\u2026","author_url":"https://blog.hatena.ne.jp/susisu/","blog_title":"Object.create(null)","published":"2015-05-03 22:57:46","html":"<iframe src=\"https://hatenablog-parts.com/embed?url=https%3A%2F%2Fsusisu.hatenablog.com%2Fentry%2F2015%2F05%2F03%2F225746\" title=\"Object.create(null) - Object.create(null)\" class=\"embed-card embed-blogcard\" scrolling=\"no\" frameborder=\"0\" style=\"display: block; width: 100%; height: 190px; max-width: 500px; margin: 10px 0px;\"></iframe>","type":"rich","image_url":null}