Auto Rename Tag
Bracket Pair Colorizer
Chinese (Traditional)
Live Server
HTML:網頁內容 h1
CSS:美化 hover
JavaScript: 互動 => 存取 =>指令
計畫 回應使用者
屬性 + 事件() = 物件Object
標籤 透過 瀏覽器 ==> 變成物件Object
Method|Function =>函式 副程式 方法
給他小背包才會執行
沒有小背包() 屬性
https://www.w3schools.com/jsref/dom_obj_document.asp
https://youtu.be/tMmpaR0EnnA?t=32
(1)Browser Object Model (BOM)
https://www.w3schools.com/js/js_window.asp
(2)The HTML DOM (Document Object Model)
DOM樹
https://www.w3schools.com/js/js_htmldom.asp
https://www.w3schools.com/js/js_syntax.asp
不可以
Hyphens: first-name, last-name, master-card, inter-city.
可以
(1)Underscore:
first_name, last_name, master_card, inter_city.
(2)Upper Camel Case (Pascal Case):
FirstName, LastName, MasterCard, InterCity.
(3)Lower Camel Case:
JavaScript programmers tend to use camel case that starts with a lowercase letter:
firstName, lastName, masterCard, interCity.
(1)倉庫,等一下拿出來用
(2)先宣告變數再使用,不要用了才宣告
雖然宣告會往上放to the top
(Hoisting is JavaScript's default behavior of moving declarations to the top.)
https://www.w3schools.com/js/js_hoisting.asp
但是還是會出錯誤:
console.log(x4);
var x4 = 25;
(1) (Template Literals):2015後,可以塞${變數},好用
`字串`
var temp = "插入文字";
var msg3 = `在我們的${temp}中間`;
console.log(msg3);
(2)''
(3)""
var a = 1;
let b = 2;
const c = 3;
var、let 可以被更改
const 不能被更改
a = 11;
b = 22;
c = 99; //會錯誤
var {}外也不受影響
let {}失效,但這樣才是合理的
if (1 == 1) {
var x = "rabbit";
let y = "bunny";
console.log(x); //rabbit
console.log(y); //bunny
}
console.log(x); //rabbit
console.log(y); //失效
var 更新宣告值
let 不能重複宣告
var cat = 99;
var cat = 55;
console.log(cat); //55
let cat = 99;
let cat = 55;
console.log(cat); //Identifier 'cat' has already been declared
behavior of moving declarations to the top
var 被往上拉而有反應
let 反正就是錯誤。(ReferenceError: Cannot access 變數名稱 before initialization(???))
var
x3 = 20;
console.log(x3); //20
var x3;
console.log(x4); //undefined
var x4 = 25;
let
y3 = 20;
console.log(x3);
let x3;
console.log(x4);
let y4 = 25;
finction aaa(){
var bbb = 10 //生命週期在finction內
}
regexp只是個說明(可以放甚麼? 可以放字串 |或 RegExp 正規表示法)
:RegExpMatchArray回傳甚麼樣的值
Console 檢查用
Network 載入時間
Application 暫時性存放資料
Ctrl + D => 整體改變
Alt +上下 => 移動
Alt + Shift +上下 => 複製
Alt + Shift 多行選取
我需要的分隔線XD
console.log('\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n');