Javascript Advance and Modules

as javascript program becomes complex, it has new concepts of modules, (like python module, a library of functions)
as javascript is inside different browser, means it needs browser support, modern new browser has support new feature of js, but js need to tell them, how modern this JS code is, like type attribute.
```
<!doctype html>
<script type="module">
  // note: module need browser access via http, not file:///
  import {sayHi} from './say.js';
  document.body.innerHTML = sayHi('John');
</script>
```
ref: https://javascript.info/js

ref : https://zellwk.com/blog/es6/

new let vs var

let a = 1 // block scope; local block accessible only
var b = 1 // function scope; global accessible when global declare, local only when local declare

unpack assignment (destructuring assignment, as from js1.7 = ES6)

[a, b] = [10, 20]; // Destructuring arrays
// same as  pyhton: a,b = [10,20]
const my_data = {
  firstName: 'Any',
  lastName: 'One'
}
let { firstName, lastName } = my_data // destructuring objects, note the variable name must be same as key name

time left countdown (pure js): https://www.codegrepper.com/code-examples/javascript/make+time+left+from+date.now+javascript
javascript date and timezone: https://flaviocopes.com/javascript-dates/
time related lib: https://momentjs.com/timezone/

confetti from tsparticles:
- https://dev.to/matteobruni/how-to-create-beautiful-confetti-animations-with-tsparticles-193
- https://github.com/matteobruni/tsparticles
button click confetti:
- https://codemyui.com/confetti-pop-out-on-button-click/

Javascript Advance and Modules

other new ES6 codes

Useful code