Salesforce Lightning: How to deal with cookies

You can use the below helper method to create a cookie.

So as an example, to create a cookie that stores the name of a visitor, you can call the helper method like below:

helper.createCookie('username', 'John Doe', 7);

To create a session cookie, don't pass any value for days. So you will be calling the helper method like below:

helper.createCookie('username', 'John Doe');

After executing the code above, the name of the cookie generated is LSKey[c]username. The name of the cookie is prefixed with LSKey[<c>] where c is the namespace. So to retrieve the value of this cookie, use the below code:

So as an example, to retrieve the cookie value, you can call the helper method like below:

helper.getCookie('username');

Check the link in the references section to check how to delete the cookie.

References: https://www.sitepoint.com/how-to-deal-with-cookies-in-javascript/