Get cookie by name

Question

I have a getter to get the value from a cookie.

Now I have 2 cookies by the name shares= and by the name obligations= .

I want to

Answer 1

use a cookie getting script:

function readCookie(name) {
    var nameEQ = name + "=";
    var ca = document.cookie.split(';');
    for(var i=0;i < ca.length;i++) {
        var c = ca[i];
        while (c.charAt(0)==' ') c = c.substring(1,c.length);
        if (c.indexOf(nameEQ) == 0) return c.substring(nameEQ.length,c.length);
    }
    return null;
}

then call it:

var value = readCookie('obligations');

i stole the code above from quirksmode cookies page. you should read it.

Answer 2

set by javascript

document.cookie = 'cookiename=tesing';

get by jquery with the jquery-cookie plugin

var value = $.cookie("cookiename");

alert(value);

Answer 3

If you use jQuery I recommend you to use this plugin:

https://github.com/carhartl/jquery-cookie
https://github.com/carhartl/jquery-cookie/blob/master/jquery.cookie.js

<script type="text/javascript"
 src="//cdnjs.cloudflare.com/ajax/libs/jquery-cookie/1.4.1/jquery.cookie.min.js">

So you can read cookie like this:

var value = $.cookie("obligations");

Also you can write cookie:

$.cookie('obligations', 'new_value');
$.cookie('obligations', 'new_value', { expires: 14, path: '/' });

Delete cookie:

$.removeCookie('obligations');

Answer 4

One approach, which avoids iterating over an array, would be:

function getCookie(name) {
  const value = `; ${document.cookie}`;
  const parts = value.split(`; ${name}=`);
  if (parts.length === 2) return parts.pop().split(';').shift();
}

Walkthrough

Splitting a string by token will produce either, an array with one string (same value), in case token does not exist in a string, or an array with two strings , in case token is found in a string .

The first (left) element is string of what was before the token, and the second one (right) is what is string of what was after the token.

(NOTE: in case string starts with a token, first element is an empty string)

Considering that cookies are stored as follows:

"{name}={value}; {name}={value}; ..."

in order to retrieve specific cookie value, we just need to get string that is after "; {name}=" and before next ";". Before we do any processing, we prepend the cookies string with "; ", so that every cookie name, including the first one, is enclosed with "; " and "=":

"; {name}={value}; {name}={value}; ..."

Now, we can first split by "; {name}=", and if token is found in a cookie string (i.e. we have two elements), we will end up with second element being a string that begins with our cookie value. Then we pull that out from an array (i.e. pop), and repeat the same process, but now with ";" as a token, but this time pulling out the left string (i.e. shift) to get the actual token value.

Answer 5

My one linear function to get the value cookie by its key.

cookie = key=>((new RegExp((key || '=')+'=(.*?); ','gm')).exec(document.cookie+'; ') ||['',null])[1]

Call cookie function as

cookie('some-key')

Answer 6

always works well:

function getCookie(cname) {
    var name = cname + "=",
        ca = document.cookie.split(';'),
        i,
        c,
        ca_length = ca.length;
    for (i = 0; i < ca_length; i += 1) {
        c = ca[i];
        while (c.charAt(0) === ' ') {
            c = c.substring(1);
        }
        if (c.indexOf(name) !== -1) {
            return c.substring(name.length, c.length);
        }
    }
    return "";
}

function setCookie(variable, value, expires_seconds) {
    var d = new Date();
    d = new Date(d.getTime() + 1000 * expires_seconds);
    document.cookie = variable + '=' + value + '; expires=' + d.toGMTString() + ';';
}

No requirements for jQuery or anything. Pure old good JavaScript.