Cookies allow a website to store information about a user in the browser. This way if the site refreshes or the user leaves and comes back later the data can be preserved. Cookies also get sent along with requests to the server. A server can give the browser a session cookie after the user logs in. This way every time the user sends something to the server it can just check for a valid session to make sure the user is authorized to perform a certain action.
Note: Keep in mind that the cookies will get sent to the server with every request so you should store a minimal amount of data in them. If you need more space or you don’t need to send data to the server with every request consider using the browser local storage.
Security considerations: If you plan on using cookies for authentication/authorization watch out for CSRF(Cross Site Request Forgery).
Let’s see the example below.
//Add a cookie:///////////////////////////////////////////// //window.document.cookie = "TestCookie=Test"; //window can be left out and it will still work. document.cookie = "TestCookie=Test"; // "cookie name"="value you want to store" //Setting the expiration date of a cookie. //Year, month, day document.cookie = "TestCookie=Test; expires=" + new Date(3021, 0, 1).toUTCString(); //This cookie would last for a 1000 years. //Get cookies://///////////////////////////////////////////// //You will get all the cookies as a string. console.log(document.cookie);