Create, Read and Delete Cookies with JavaScript

In this tutorial, I am going to give a JavaScript code samples to create, read and delete the cookies.

Setting a Cookie

 
function SetCookie(name,value,days) {
 var now= new Date();
 var expDate = new Date();
 if (days==null || days==0) days=1;
 //create date after no of "days" from now
 expDate.setTime(now.getTime() + 3600000*24*days);
 
 //create cookie with name, value and expire date
 document.cookie=name+"="+escape(value)+";expires="+expDate.toUTCString();
}

Call the above function to set the cookie:

 
  SetCookie("testCookie","testval",30); 

The Cookie “testCookie” has the value “testval” and expires in 30 days.

Reading a Cookie

 
ReadCookie("testCookie"); // Returns value "testval"

function ReadCookie(name) {
 if (name == "") return "";
 var strCookie =" " + document.cookie;
 var idx = strCookie.indexOf(" " + name + "=");
 if (idx == -1) idx = strCookie.indexOf(";" + name + "=");
 if (idx == -1) return "";

 var idx1 = strCookie.indexOf(";", idx+1);
 if (idx1 == -1) idx1 = strCookie.length; 
 return unescape(strCookie.substring(idx + name.length+2, idx1));
}

Reading a Cookie With RegExp

This is another version of ReadCookie method using Regular Expression.

 
function ReadCookie(name) {
 name = name.replace(/([.\\+\-*:\/?!|^${}()\[\]])/g, '\\$1');
 var re = new RegExp('[; ]' + name + '=([^\\s;]*)');
 var sMatch = (' ' + document.cookie).match(re);

 if (name && sMatch) return unescape(sMatch[1]);
 return '';
}

Deleting a Cookie

To delete a cookie with a given name, set a cookie that has the same name and an expiration date in the past.

 
SetCookie("testCookie","",-1); 

How do you find cookies enabled?

To know whether cookies are enabled, you can set a cookie with non-empty value and then retrieve it. If the retrieved cookie value is the same as you’ve just set, then cookies are enabled. If the retrieved value is an empty string, then cookies are disabled.