Test if an element exists before using it
var someEle = document.querySelector("#some_id"); if(typeof (someEle) != "undefined" && someEle != null){ }
Vanilla JS equivalent to jQuery.ready()
// vanilla js equivalent of jquery.ready document.addEventListener("DOMContentLoaded", function() { // do stuff on page load });
Quickly Enable/Disable Javascript (Chrome)
- open developer tools
- Cmd + Shift + p
- type: javascript
- click enable / disable Javascript
(writable) Global var
(writable) Global var (hack) in ES6 accessible from any file
https://stackoverflow.com/questions/33875322/javascript-and-es6-global-variables
An important note on Javascript modules and scope
module features are imported into the scope of a single script — they aren’t available in the global scope. Therefore, you will only be able to access imported features in the script they are imported into, and you won’t be able to access them from the JavaScript console, for example. more here: Modules Mozilla
e.g.
import * as cook from './cookie-functions.js';
Everything imported from cookie-functions.js is available/visile only in the script where the import is.