使用 HTML + Typescript 建構客戶端應用的平台與框架
基本構成要素 : NgModule , 為元件提供了編譯的上下文環境
把相關的程式碼收集到一些功能中,至少會有一個用於引導應用的 根模組
還會有很多特性模組
元素定義檢視
:::info
Components define views, which are sets of screen elements that Angular can choose among and modify according to your program logic and data.
ref: https://javascript.info/operators#increment-decrement
Increment and Decrement
increment ( ++ ) increases a variable by 1
decrement ( -- ) decreases a variable by 1
Increment/decrement can only be applied to variables. Trying to use it on a value like 5++ will give an error.
The operators ++ and -- can be placed either before or after a variable.
ref: https://javascript.info/nullish-coalescing-operator
polyfills 自動補完函式庫
A polyfill, or polyfiller, is a piece of code (or plugin) that provides the technology that you, the developer, expect the browser to provide natively. Flattening the API landscape if you will.
要注意瀏覽器支援度
Nullish coalescing operator ??
空值合併