var a = {}, b = [], c = 'hoge', d = new String('hoge'); typeof a; // "object" typeof b; // "object" ← ファッ?! typeof c; // "string" typeof d; // "object" ← ファッ?! Object と Array を区別してくれないとかないわー。new String()使うことないけど、区別しちゃうとかないわー。 ということで以前に自分が日本語訳したJavaScript Gardenにも書いてあった方法を使うと 判別が楽になるんじゃないかと。 function is(type, obj) { var clas = Object.prototype.toString.call(obj).slice(8, -1); return obj !== undefin
![JavaScriptでオブジェクトの型を判別するのにtypeof演算子使うとツラいよね - Qiita](https://cdn-ak-scissors.b.st-hatena.com/image/square/88f8feca31b4b4873f2fe26095796d97f49b130c/height=288;version=1;width=512/https%3A%2F%2Fqiita-user-contents.imgix.net%2Fhttps%253A%252F%252Fcdn.qiita.com%252Fassets%252Fpublic%252Farticle-ogp-background-412672c5f0600ab9a64263b751f1bc81.png%3Fixlib%3Drb-4.0.0%26w%3D1200%26mark64%3DaHR0cHM6Ly9xaWl0YS11c2VyLWNvbnRlbnRzLmltZ2l4Lm5ldC9-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%26mark-x%3D142%26mark-y%3D57%26blend64%3DaHR0cHM6Ly9xaWl0YS11c2VyLWNvbnRlbnRzLmltZ2l4Lm5ldC9-dGV4dD9peGxpYj1yYi00LjAuMCZoPTc2Jnc9NzcwJnR4dD0lNDBMYXl6aWUmdHh0LWNvbG9yPSUyMzFFMjEyMSZ0eHQtZm9udD1IaXJhZ2lubyUyMFNhbnMlMjBXNiZ0eHQtc2l6ZT0zNiZ0eHQtYWxpZ249bGVmdCUyQ3RvcCZzPTEwMDNjZTg4YjExNmU4MzQyNTAzZTUxMTA1YjFiNTRh%26blend-x%3D142%26blend-y%3D436%26blend-mode%3Dnormal%26txt64%3DaW4g5qCq5byP5Lya56S-44Oh44OJ44Os44O8%26txt-width%3D770%26txt-clip%3Dend%252Cellipsis%26txt-color%3D%25231E2121%26txt-font%3DHiragino%2520Sans%2520W6%26txt-size%3D36%26txt-x%3D156%26txt-y%3D536%26s%3D93c6f6736881280e8ce5f3e0177ab7f5)