[JavaScript] 解決在 IE 11 出現 'Promise' 未經定義的錯誤

又是一個遇到老瀏覽器不支援新東西的問題

自從拔掉 jQuery 的 $.ajax，改採用 axios 處理非同步資料讀取，IE 11 噴出以下訊息



在不想改變現有寫法下，找到解決的方法，直接用 Promise Polyfill。

Lightweight ES6 Promise polyfill

可以直接引用 CDN

<script src="https://cdn.jsdelivr.net/npm/promise-polyfill@8/dist/polyfill.min.js"></script>

或是下載檔案使用

實驗結果，以最快速確認可行性，就是直接引入 CDN，結果成功！還好不用再改寫法～收工，繼續下一題。

[HTML] Conditional Comments

When dealing with HTML and CSS, the most difficult part is to get everything work in different browsers.

Some hack tips:
In CSS, the way I use to code for different browsers (usually IE and FF) is '!important'.
However, it seems that IE 7 understands this magic command while IE 6 doesn't. It makes more difficult to recognize IE 7 and FF.

Here is the solution: Conditional Comments
simple way to check IE version

<!--[if IE 6]>
Using Internet Explorer 6.
<![endif]-->

or check the condition: [if !IE] => for FF