{"html":"<iframe src=\"https://hatenablog-parts.com/embed?url=https%3A%2F%2Fmonjudoh.hatenablog.com%2Fentry%2F20120904%2F1346764216\" title=\"JavaScript\u3067\u306ebuilt-in/DOM object\u306eprototype\u62e1\u5f35 - monjudoh\u2019s diary\" class=\"embed-card embed-blogcard\" scrolling=\"no\" frameborder=\"0\" style=\"display: block; width: 100%; height: 190px; max-width: 500px; margin: 10px 0px;\"></iframe>","provider_url":"https://hatena.blog","provider_name":"Hatena Blog","width":"100%","author_name":"monjudoh","height":"190","type":"rich","description":"@rosylilly\u304c\u6c17\u306b\u3057\u3066\u3044\u305f \u306e\u3067\u307e\u3068\u3081\u305f\u3002 built-in/DOM object\u306eprototype\u62e1\u5f35\u306b\u3088\u308b\u5f0a\u5bb3 \u8ffd\u52a0\u3057\u305f\u30d7\u30ed\u30d1\u30c6\u30a3/\u30e1\u30bd\u30c3\u30c9\u304cfor in\u3067\u5217\u6319\u3055\u308c\u308b var obj = {a:1}; for (var i in obj) { console.log(i); } \u3053\u3046\u3059\u308b\u3068a\u3060\u3051\u51fa\u308b\u306f\u305a\u304c\u3001 Object.prototype.b=function(){}; \u3053\u3046\u3057\u305f\u5f8c\u3060\u3068a,b\u304c\u51fa\u3066\u3057\u307e\u3046\u3063\u3066\u5974\u3067\u3059\u306d\u3002 \u305d\u306e\u307e\u307e\u4ee3\u5165\u3057\u306a\u3044\u3067Object.defineProperty/defineProperties\u3067enumerable:false\u306e\u30d7\u30ed\u30d1\u30c6\u30a3\u3068\u3057\u3066\u5b9a\u7fa9\u3059\u308c\u3070\u5217\u6319\u2026","author_url":"https://blog.hatena.ne.jp/monjudoh/","url":"https://monjudoh.hatenablog.com/entry/20120904/1346764216","image_url":null,"version":"1.0","published":"2012-09-04 22:10:16","categories":["JavaScript"],"blog_url":"https://monjudoh.hatenablog.com/","blog_title":"monjudoh\u2019s diary","title":"JavaScript\u3067\u306ebuilt-in/DOM object\u306eprototype\u62e1\u5f35"}