JS數據類型檢測的四種方法

原創 MastHead 2020-06-24 09:42

1.type of  返回值：number string boolean undefined function object.

2. intanceof 功能:檢測一個實例是否屬於一個類；返回值：true或false

3.constructor構造函數

4.Object.prototype.toString.call() 

Object.prototype.toString.call([])//

發表評論
所有評論
還沒有人評論，想成為第一個評論的人麼? 請在上方評論欄輸入並且點擊發布.
相關文章

16張圖解鎖Spring的整體脈絡

{"type":"doc","content":[{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null},"content":[{"typ

4ye 2021-12-04 13:03:55

JavaScript 瀏覽器統治地位不保？Python 有望取代

{"type":"doc","content":[{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null},"content":[{"typ

闫园园 2021-12-02 17:58:57

分享8個可以編譯爲JavaScript的語言

{"type":"doc","content":[{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null},"content":[{"typ

devpoint 2021-12-01 18:44:00

2021 最佳開源軟件榜單出爐，Flutter、StreamNative 上榜

{"type":"doc","content":[{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null},"content":[{"typ

辛晓亮 2021-12-01 11:18:54

TypeScript 4.5 發佈，帶來 Promise 功能改進

{"type":"doc","content":[{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null},"content":[{"typ

辛晓亮 2021-11-19 11:23:57

Angular 13 發佈：全面棄用 View Engine

{"type":"doc","content":[{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null},"content":[{"typ

闫园园 2021-11-05 17:43:56

微軟產品經理：你不能不知道的6個Web開發者工具

{"type":"doc","content":[{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null}},{"type":"paragr

Christian Heilmann 2021-11-03 16:08:56

看完 Jamstack 的調查報告，我抓住了最新的 Web 流行趨勢

{"type":"doc","content":[{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null},"content":[{"typ

辛晓亮 2021-10-13 17:13:59

開發者眼中的 HarmonyOS 遊戲生態：有紅利也有挑戰

{"type":"doc","content":[{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null},"content":[{"typ

罗燕珊 2021-09-22 12:13:51

邊緣服務的一致性、耦合和複雜性

{"type":"doc","content":[{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null},"content":[{"typ

Glenn Engstrand 2021-09-08 15:08:54

技術人最愛Rust，最怕COBOL，工程經理最高薪，懂Clojure最賺錢 | 2021全球開發者報告

{"type":"doc","content":[{"type":"heading","attrs":{"align":null,"level":2},"content":[{"type":"text","text":"概述"}]},{"t

Stack Overflow 2021-08-09 14:38:55

深入學習 React 合成事件

{"type":"doc","content":[{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null},"content":[{"typ

微医大前端技术 2021-07-31 20:03:59

如何從 0 到 1 搭建性能檢測系統

{"type":"doc","content":[{"type":"heading","attrs":{"align":null,"level":2},"content":[{"type":"text","text":"前言"}]},{"t

政采云前端团队 2021-07-31 17:03:58

你不知道的 TypeScript 高級技巧

{"type":"doc","content":[{"type":"heading","attrs":{"align":null,"level":2},"content":[{"type":"text","text":"前言"}]},{"t

微医大前端技术 2021-07-31 11:03:58

編寫高質量可維護的代碼：異步優化

{"type":"doc","content":[{"type":"heading","attrs":{"align":null,"level":1},"content":[{"type":"text","text":"前言"}]},{"t

政采云前端团队 2021-07-31 10:03:55