====== Javascript ======

===== 數組 =====

計算交集、合集、補集
<code javascript>
var a = [1,2,3,4,5]
var b = [2,4,6,8,10]
//交集
var c = a.filter(function(v){ return b.indexOf(v) > -1 })
//差集
var d = a.filter(function(v){ return b.indexOf(v) == -1 })
//补集
var e = a.filter(function(v){ return !(b.indexOf(v) > -1) })
        .concat(b.filter(function(v){ return !(a.indexOf(v) > -1)}))
//并集
var f = a.concat(b.filter(function(v){ return !(a.indexOf(v) > -1)}));
</code>

===== 同步 =====

Critical Resources : [[https://www.npmjs.com/package/async-lock|async-lock]]

加密
<code javascript>
import crypto from 'crypto'

function HMAC_SHA256(data, secret) {
  return crypto.createHmac('sha256', secret).update(data).digest('base64');
}
</code>


网页地址编码： <color #ff7f27>''%%encodeURIComponent(string)%%''</color>

===== 反编译 =====

JS Beautifier (https://beautifier.io/)
Code Beautify (https://codebeautify.org/js-beautifier)
Prettier (https://prettier.io/playground/)
Online JavaScript Beautifier (https://www.freeformatter.com/javascript-beautifier.html)
Codepen (https://codepen.io/)