{"type":"rich","description":"\u6bce\u56de\u8abf\u3079\u3066\u3044\u308b\u306e\u3067\u81ea\u5206\u7528\u30e1\u30e2 var foo = function(bar){ if(bar === undefined){ bar = {}; } //your code ... }; undefined\u304c\u4e0a\u66f8\u304d\u3055\u308c\u308b\u53ef\u80fd\u6027\u3082\u3042\u308a\u307e\u3059\u304c\u3001 \u57fa\u672c\u7684\u306b\u305d\u3093\u306a\u72b6\u614b\u306b\u306f\u306a\u3089\u306a\u3044\u306f\u305a\u306a\u306e\u3067typeof\u306b\u3088\u308b\u578b\u5224\u5b9a\u307e\u3067\u306f\u3057\u3066\u3044\u307e\u305b\u3093\u3002 \u30c1\u30fc\u30e0\u5168\u4f53\u3067\u4f7f\u3046\u30e9\u30a4\u30d6\u30e9\u30ea\u3068\u3057\u3066\u4f5c\u3063\u3066\u304a\u304f\u306a\u3089typeof\u307e\u3067\u3084\u3063\u3066\u3082\u3044\u3044\u304b\u3082\u3002\u307e\u305f\u3001AngularJS\u4f7f\u3063\u3066\u3044\u308b\u306a\u3089angular.isUndefined\u304c\u3042\u308b\u306e\u3067\u3001\u305d\u308c\u3092\u4f7f\u3044\u307e\u3059\u3002 var foo = function(bar){ if(angular.isUndef\u2026","html":"<iframe src=\"https://hatenablog-parts.com/embed?url=https%3A%2F%2Fkkkw.hatenablog.jp%2Fentry%2Fjavascript%2Fdefault-args\" title=\"JavaScript\u3067\u30c7\u30d5\u30a9\u30eb\u30c8\u306e\u5f15\u6570\u3092\u5b9f\u73fe\u3055\u305b\u308b - kikukawa&#39;s diary\" class=\"embed-card embed-blogcard\" scrolling=\"no\" frameborder=\"0\" style=\"display: block; width: 100%; height: 190px; max-width: 500px; margin: 10px 0px;\"></iframe>","width":"100%","author_url":"https://blog.hatena.ne.jp/devillikeaangel/","blog_title":"kikukawa's diary","height":"190","author_name":"devillikeaangel","categories":["JavaScript","AngularJS"],"title":"JavaScript\u3067\u30c7\u30d5\u30a9\u30eb\u30c8\u306e\u5f15\u6570\u3092\u5b9f\u73fe\u3055\u305b\u308b","provider_url":"https://hatena.blog","blog_url":"https://kkkw.hatenablog.jp/","published":"2014-11-27 11:18:45","url":"https://kkkw.hatenablog.jp/entry/javascript/default-args","image_url":null,"version":"1.0","provider_name":"Hatena Blog"}