global variables for different javascript file

Question

I have a web app, which has 2 html pages(html1,html2 related to javascript file js1.js,js2.js) When I click a button on html1, it will navigate to html2. I know there is the way transfer the parameter using url from html1/js1/js to html2/js2.js.

Is there a mechanism that set up variables both j1.js j2.js can access?(likes global variable in c)

Welcome any comment?

Answer 1

This is not directly possible as each page loads with its own window object namespace.

ie A global variable in js1.js (used in page1.html) is actually a member of the window object in page1. Similarly a global variable in page2.html is a member of that page's window object. The 2 window objects are totally different in the sense there is no site wide window or site object that can store global variable for use throughout a site

You can however use window.localStorage to share variables/values across pages in your site.

Example :

Setting value:

window.localStorage.setItem('myglobal', "hello");

Getting value:

var myglobal = window.localStorage.getItem('myglobal');

Answer 2

Variables and values can be passed through pages via querystring. Have a look at this SO article .

If you strictly need to create a Javascript global variable, then you have to include a common snippet in both pages:

var myGlobalVar;

But this only represent a storage accessible by both scripts. You have to set its value anyway.

Answer 3

A hackish solution is to store it into the window.name field. This is shared in the same window/tab of the browser. I personally don't like it. That variable isn't meant to be used this way.

There are libraries to persist state: http://pablotron.org/?cid=1557

Or, you could write your own code to store the variable in session (requires server-side programming), in HTML5 storage, in cookies, etc.

Answer 4

You can either parse window.location.href to extract the parameters, set cookies in one page and retrieve them in the other ( example here ) which also requires parsing or use a server-side solution.

Most probably if you look for in interwebs you can find parsers for URLs and Cookies.