jQuery check if Cookie exists, if not create it

Question

I cannot get this code to work I must be missing something pretty simple. I am trying to check to see if a Cookie exists, if it does {do nothing} if it doesn't {create it}. I am testing the cookie by including an alert on a page. Basically I do not want the cookie to keep re-creating with a referral url, I am trying to grab only the FIRST referred URL.

$(document).ready(function(){   
  if ($.cookie('bas_referral') == null ){
   var ref = document.referrer.toLowerCase();  
   // set cookie  
   var cookURL =  $.cookie('bas_referral', ref, { expires: 1 }); 
  } 
 });

Displaying the current cookie contents:

    // get cookie  
    alert($.cookie('bas_referral'));  

    // delete cookie  
     $.cookie('bas_referral', null);

Appears to be working just fine: http://jsfiddle.net/niklasvh/wxFvG/. Have you included the `$.cookie` plugin source code in your page? — Niklas, Jun 15 '11 at 18:48
Are you opening the page by HTTP? (and thus not from local disk file system) What cookie plugin are you using? What time unit is the expires value? Seconds? So, it expires in 1 second? — BalusC, Jun 15 '11 at 18:48
I am using the jquery.cookie.js plugin and my alert displays the previous URL I was on, so I believe the cookie is being created. HOWEVER, if I were to go to different pages throughout the site, the alert displaying the cookie URL will change, it shouldn't being I set an IF-Statement. — ToddN, Jun 15 '11 at 18:54

score 86 · Accepted Answer · edited Feb 17 '17 at 07:37

86

I think the bulletproof way is:

if (typeof $.cookie('token') === 'undefined'){
 //no cookie
} else {
 //have cookie
}

Checking the type of a null, empty or undefined var always returns 'undefined'

Edit: You can get there even easier:

if (!!$.cookie('token')) {
 // have cookie
} else {
 // no cookie
}

!! will turn the falsy values to false. Bear in mind that this will turn 0 to false!

edited Feb 17 '17 at 07:37

Snowball

1,402
2
17
31

answered Apr 28 '14 at 15:11

Laszlo

2,225
19
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2

WARNING: typeof null === 'object' as Dan comments below. – Jan Żankowski Mar 19 '15 at 10:36
this is the correct answer for the given question, @foo! While I tested the code, the true false context was vice versa: if (!!$.cookie('token')) { // have cookie } else { // no cookie } – yesfabime Nov 30 '15 at 06:07
1

woah! it checks null, empty and undefined! Didn't know there's a shorter way to check those three before. Nice – Lyka Apr 08 '16 at 04:46
what if the value of the cookie was `false`? probably better to check `null` and `undefined` – Atav32 Jun 16 '16 at 21:46
1

@foo the shorter answer isnt working for me. it is showing the opposite as to what the answer says - for me at least! – Paul Fitzgerald Dec 09 '16 at 12:45
The short answer with `!!` will trigger the eslint style check error: `no-extra-boolean-cast`. Better to use the typeof check, just in case – Vlad Preda Apr 28 '17 at 10:41
My non-existing cookies were "null" but not "undefined" – WebMW Jan 22 '20 at 19:58
hey @WebMW see the **Edit** section: `!!$.cookie('token')` returns `false` – Laszlo Jan 23 '20 at 15:04
add this in your header to make sure it works – Teo Mihaila Jan 27 '22 at 18:24

inertialmedia · Answer 2 · 2011-12-16T16:44:04.817

26

 $(document).ready(function() {

     var CookieSet = $.cookie('cookietitle', 'yourvalue');

     if (CookieSet == null) {
          // Do Nothing
     }
     if (jQuery.cookie('cookietitle')) {
          // Reactions
     }
 });

edited Dec 16 '11 at 16:44

answered Dec 16 '11 at 16:24

inertialmedia

518
7
14

2

i don't know why but this is setting a cookie, not checking if one exists, very strange! – luke_mclachlan Mar 18 '15 at 00:57
var CookieSet = $.cookie('cookietitle', 'yourvalue'); not works on my pc, what can be the reason? I'm using although jquery 1.9.1 library. – Bengi Besçeli May 17 '15 at 12:46
1

Hmm I found the reason; I didn't have been installed the plugin from GitHub, I realised this was a native function. People who read this should download the plugin from (thank you @Kazar) : https://github.com/carhartl/jquery-cookie – Bengi Besçeli May 17 '15 at 13:12

score 9 · Answer 3 · edited Mar 27 '15 at 12:14

I was having alot of trouble with this because I was using:

if($.cookie('token') === null || $.cookie('token') === "")
{
      //no cookie
}
else
{
     //have cookie
}

The above was ALWAYS returning false, no matter what I did in terms of setting the cookie or not. From my tests it seems that the object is therefore undefined before it's set so adding the following to my code fixed it.

if($.cookie('token') === null || $.cookie('token') === "" 
    || $.(cookie('token') === "null" || $.cookie('token') === undefined)
{
      //no cookie
}
else
{
     //have cookie
}

score 2 · Answer 4 · edited Jul 10 '17 at 10:02

You can set the cookie after having checked if it exists with a value.

 $(document).ready(function(){            
      if ($.cookie('cookie')) { //if cookie isset
         //do stuff here like hide a popup when cookie isset
         //document.getElementById("hideElement").style.display = "none";
      }else{
         var CookieSet = $.cookie('cookie', 'value'); //set cookie
      }       
 });

score 1 · Answer 5 · answered Apr 27 '18 at 04:14

1

Try this very simple:

            var cookieExist = $.cookie("status");
            if(cookieExist == "null" ){
                alert("Cookie Is Null");

            }

answered Apr 27 '18 at 04:14

Aldrin Masamoc Mojica

221
2
8

jQuery check if Cookie exists, if not create it

5 Answers5

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