CODEWITHSUNDEEP
javascripthtmllocal-storagesessionstorage
Christophe
Christophe

Reputation: 28124

Scope of sessionStorage and localStorage

I read some documentation on sessionStorage and localStorage, but I don't understand what the scope is: the domain, a specific page?

For example, if I have the following pages:

http://example.com/products.aspx?productID=1

http://example.com/products.aspx?productID=2

http://example.com/services.aspx?serviceID=3

And if on each of the above pages I run (with idvalue being the value in the querystring):

localStorage.setItem('ID',idvalue);

Am I going to end up with 3 different values stored, or are the values going to overwrite each other?

Upvotes: 118

Views: 105639

Answers (2)

Talha
Talha

Reputation: 19252

Session Storage:

  1. Values persist only as long as the window or tab in which they are stored.

  2. Values are only visible within the window or tab that created them.

Local Storage:

  1. Values persist window and browser lifetimes.

  2. Values are shared across every window or tab running at the same origin.

So, by reading and understanding this each key-value pair is unique for each domain, because local storage persist values across window or tab.

Upvotes: 169

Rob W
Rob W

Reputation: 348992

The values are going to overwrite each other. Each key-name pair is unique for a protocol and domain, regardless of the paths.

The affected domain can be changed via the document.domain property.

  • sub.example.com -> example.com is possible (subdomain)
  • sub.example.com -> other.example.com is not possible

References:

  • MDN: Web Storage API: "sessionStorage maintains a separate storage area for each given origin [...]"
  • MDN: Origin: "Two objects have the same origin only when the scheme, hostname, and port all match."

Upvotes: 107

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