JS Cookies

Cookies enable the storage of user information on web pages.

What are Cookies?

Cookies are small pieces of data stored in text files on your computer.

After a web server sends a page to a browser and the connection is closed, the server loses all information about the user.

Cookies were created to address the problem of “how to remember information about the user”:

For instance, when a user visits a web page, their name can be stored in a cookie.
The next time the user visits, the cookie “remembers” their name.

Cookies are stored as name-value pairs, such as:

username = John Doe

When a browser requests a web page from a server, the cookies associated with that page are included in the request. This allows the server to access the data needed to “remember” information about the user.

None of the examples below will function if your browser has disabled support for local cookies.

Create a Cookie with JavaScript

JavaScript can create, read, and delete cookies using the document.cookie property.

A cookie can be created in JavaScript like this:

document.cookie = “username=John Doe”;

You can specify an expiry date (in UTC time). By default, the cookie is removed when the browser is closed.

document.cookie = “username=John Doe; expires=Thu, 18 Dec 2013 12:00:00 UTC”;

By using a path parameter, you can specify the path to which the cookie belongs. By default, the cookie is associated with the current page.

document.cookie = “username=John Doe; expires=Thu, 18 Dec 2013 12:00:00 UTC; path=/”;