Develop Reference

How to pass variables from one file to another? [duplicate]

How can I create and read a value from a cookie in JavaScript?

Here are functions you can use for creating and retrieving cookies.
function createCookie(name, value, days) {
var expires;
if (days) {
var date = new Date();
date.setTime(date.getTime() + (days * 24 * 60 * 60 * 1000));
expires = "; expires=" + date.toGMTString();
}
else {
expires = "";
}
document.cookie = name + "=" + value + expires + "; path=/";
}
function getCookie(c_name) {
if (document.cookie.length > 0) {
c_start = document.cookie.indexOf(c_name + "=");
if (c_start != -1) {
c_start = c_start + c_name.length + 1;
c_end = document.cookie.indexOf(";", c_start);
if (c_end == -1) {
c_end = document.cookie.length;
}
return unescape(document.cookie.substring(c_start, c_end));
}
}
return "";
}

Minimalistic and full featured ES6 approach:
const setCookie = (name, value, days = 7, path = '/') => {
const expires = new Date(Date.now() + days * 864e5).toUTCString()
document.cookie = name + '=' + encodeURIComponent(value) + '; expires=' + expires + '; path=' + path
}
const getCookie = (name) => {
return document.cookie.split('; ').reduce((r, v) => {
const parts = v.split('=')
return parts[0] === name ? decodeURIComponent(parts[1]) : r
}, '')
}
const deleteCookie = (name, path) => {
setCookie(name, '', -1, path)
}

JQuery Cookies
or plain Javascript:
function setCookie(c_name,value,exdays)
{
var exdate=new Date();
exdate.setDate(exdate.getDate() + exdays);
var c_value=escape(value) + ((exdays==null) ? "" : ("; expires="+exdate.toUTCString()));
document.cookie=c_name + "=" + c_value;
}
function getCookie(c_name)
{
var i,x,y,ARRcookies=document.cookie.split(";");
for (i=0; i<ARRcookies.length; i++)
{
x=ARRcookies[i].substr(0,ARRcookies[i].indexOf("="));
y=ARRcookies[i].substr(ARRcookies[i].indexOf("=")+1);
x=x.replace(/^\s+|\s+$/g,"");
if (x==c_name)
{
return unescape(y);
}
}
}

ES7, using a regex for get(). Based on MDN
const Cookie = {
get: name => {
let c = document.cookie.match(`(?:(?:^|.*; *)${name} *= *([^;]*).*$)|^.*$`)[1]
if (c) return decodeURIComponent(c)
},
set: (name, value, opts = {}) => {
/*If options contains days then we're configuring max-age*/
if (opts.days) {
opts['max-age'] = opts.days * 60 * 60 * 24;
/*Deleting days from options to pass remaining opts to cookie settings*/
delete opts.days
}
/*Configuring options to cookie standard by reducing each property*/
opts = Object.entries(opts).reduce(
(accumulatedStr, [k, v]) => `${accumulatedStr}; ${k}=${v}`, ''
)
/*Finally, creating the key*/
document.cookie = name + '=' + encodeURIComponent(value) + opts
},
delete: (name, opts) => Cookie.set(name, '', {'max-age': -1, ...opts})
// path & domain must match cookie being deleted
}
Cookie.set('user', 'Jim', {path: '/', days: 10})
// Set the path to top level (instead of page) and expiration to 10 days (instead of session)
Usage - Cookie.get(name, value [, options]):
options supports all standard cookie options and adds "days":
path: '/' - any absolute path. Default: current document location,
domain: 'sub.example.com' - may not start with dot. Default: current host without subdomain.
secure: true - Only serve cookie over https. Default: false.
days: 2 - days till cookie expires. Default: End of session.
Alternative ways of setting expiration:
expires: 'Sun, 18 Feb 2018 16:23:42 GMT' - date of expiry as a GMT string.
Current date can be gotten with: new Date(Date.now()).toUTCString()
'max-age': 30 - same as days, but in seconds instead of days.
Other answers use "expires" instead of "max-age" to support older IE versions. This method requires ES7, so IE7 is out anyways (this is not a big deal).
Note: Funny characters such as "=" and "{:}" are supported as cookie values, and the regex handles leading and trailing whitespace (from other libs).
If you would like to store objects, either encode them before and after with and JSON.stringify and JSON.parse, edit the above, or add another method. Eg:
Cookie.getJSON = name => JSON.parse(Cookie.get(name))
Cookie.setJSON = (name, value, opts) => Cookie.set(name, JSON.stringify(value), opts);

Mozilla created a simple framework for reading and writing cookies with full unicode support along with examples of how to use it.
Once included on the page, you can set a cookie:
docCookies.setItem(name, value);
read a cookie:
docCookies.getItem(name);
or delete a cookie:
docCookies.removeItem(name);
For example:
// sets a cookie called 'myCookie' with value 'Chocolate Chip'
docCookies.setItem('myCookie', 'Chocolate Chip');
// reads the value of a cookie called 'myCookie' and assigns to variable
var myCookie = docCookies.getItem('myCookie');
// removes the cookie called 'myCookie'
docCookies.removeItem('myCookie');
See more examples and details on Mozilla's document.cookie page.
A version of this simple js file is on github.

For those who need save objects like {foo: 'bar'}, I share my edited version of #KevinBurke's answer. I've added JSON.stringify and JSON.parse, that's all.
cookie = {
set: function (name, value, days) {
if (days) {
var date = new Date();
date.setTime(date.getTime() + (days * 24 * 60 * 60 * 1000));
var expires = "; expires=" + date.toGMTString();
}
else
var expires = "";
document.cookie = name + "=" + JSON.stringify(value) + expires + "; path=/";
},
get : function(name){
var nameEQ = name + "=",
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 JSON.parse(c.substring(nameEQ.length,c.length));
}
return null;
}
}
So, now you can do things like this:
cookie.set('cookie_key', {foo: 'bar'}, 30);
cookie.get('cookie_key'); // {foo: 'bar'}
cookie.set('cookie_key', 'baz', 30);
cookie.get('cookie_key'); // 'baz'

I've used accepted answer of this thread many times already. It's great piece of code: Simple and usable. But I usually use babel and ES6 and modules, so if you are like me, here is code to copy for faster developing with ES6
Accepted answer rewritten as module with ES6:
export const createCookie = ({name, value, days}) => {
let expires;
if (days) {
let date = new Date();
date.setTime(date.getTime() + (days * 24 * 60 * 60 * 1000));
expires = '; expires=' + date.toUTCString();
} else {
expires = '';
}
document.cookie = name + '=' + value + expires + '; path=/';
};
export const getCookie = ({name}) => {
if (document.cookie.length > 0) {
let c_start = document.cookie.indexOf(name + '=');
if (c_start !== -1) {
c_start = c_start + name.length + 1;
let c_end = document.cookie.indexOf(';', c_start);
if (c_end === -1) {
c_end = document.cookie.length;
}
return unescape(document.cookie.substring(c_start, c_end));
}
}
return '';
};
And after this you can simply import it as any module (path of course may vary):
import {createCookie, getCookie} from './../helpers/Cookie';

Here's a code to Get, Set and Delete Cookie in JavaScript.
function getCookie(name) {
name = name + "=";
var cookies = document.cookie.split(';');
for(var i = 0; i <cookies.length; i++) {
var cookie = cookies[i];
while (cookie.charAt(0)==' ') {
cookie = cookie.substring(1);
}
if (cookie.indexOf(name) == 0) {
return cookie.substring(name.length,cookie.length);
}
}
return "";
}
function setCookie(name, value, expirydays) {
var d = new Date();
d.setTime(d.getTime() + (expirydays*24*60*60*1000));
var expires = "expires="+ d.toUTCString();
document.cookie = name + "=" + value + "; " + expires;
}
function deleteCookie(name){
setCookie(name,"",-1);
}
Source: http://mycodingtricks.com/snippets/javascript/javascript-cookies/

Performance benchmark
Comparison of ES6 versions of some popular getCookie functions (with my improvements):
https://www.measurethat.net/Benchmarks/Show/16012/5/getcookie-for-vs-forof-vs-indexof-vs-find-vs-reduce
TL;DR: for...of version seams to be fastest for real-life cookies data :)
Important: document.cookie can provide duplicated cookie names if there are cookies with the same name for path=/ and current page path (eg. path=/faq). But the cookie for the current path will always be the first in the string, so be aware of this when using the reduce() version from the other answer provided here (it returns the last found cookie instead of the first one).
Fixed reduce() version is further in my answer.
For..of version:
Fastest for the real-life benchmark data set (10 cookies with long values). But performance results are almost the same as with vanilla for loop and with Array.find(), so use which you like :)
function getCookieForOf(name) {
const nameEQ = name + '=';
for (const cookie of document.cookie.split('; ')) {
if (cookie.indexOf(nameEQ) === 0) {
const value = cookie.substring(nameEQ.length);
return decodeURIComponent(value); // returns first found cookie
}
}
return null;
}
IndexOf version
Incredibly fast in the artificial test set of 1000 cookies with short values (because it doesn't create an array with 1000 records). To be honest, I consider there could be a bug in the test code that makes this version so crazy fast (if you would find some, pls let me know). Anyway, it's rather not probable to have 1000 cookies in the real App ;)
It's slow for the real-world test data set with 10 long cookies.
function getCookieIndexOf(name) {
const nameEQ = name + '=';
const cookies = document.cookie;
const cookieStart = cookies.indexOf(nameEQ);
if (cookieStart !== -1) {
const cookieValueStart = cookieStart + nameEQ.length;
const cookieEnd = cookies.indexOf(';', cookieValueStart);
const value = cookies.substring(
cookieValueStart,
cookieEnd !== -1 ? cookieEnd : undefined
);
return decodeURIComponent(value); // returns first found cookie
}
return null;
}
Array.find() version
function getCookieFind(name) {
const nameEQ = name + '=';
const foundCookie = document.cookie
.split('; ')
.find(c => c.indexOf(nameEQ) === 0); // returns first found cookie
if (foundCookie) {
return decodeURIComponent(foundCookie.substring(nameEQ.length));
}
return null;
}
Vanilla, old-school, for-loop version ;)
function getCookieFor(name) {
const nameEQ = name + "=";
const ca = cookies.split('; ');
for(let i=0; i < ca.length; i++) {
const c = ca[i];
if (c.indexOf(nameEQ) === 0) {
const value = c.substring(nameEQ.length);
return decodeURIComponent(value); // returns first found cookie
}
}
return null;
}
// ES5 version:
function getCookieFor(name) {
var nameEQ = name + "=";
var ca = cookies.split('; ');
for(var i=0;i < ca.length;i++) {
var c = ca[i];
if (c.indexOf(nameEQ) === 0) {
var value = c.substring(nameEQ.length);
return decodeURIComponent(value); // returns first found cookie
}
}
return null;
}
Array.reduce() version
My fixed version of this answer from #artnikpro - returns the first found cookie, so works better with duplicated cookie names for the current path (e.g. path=/faq) and path=/.
This version is the slowest one in all performance tests, so IMHO should be avoided.
function getCookieReduce(name) {
return document.cookie.split('; ').reduce((r, v) => {
const [n, ...val] = v.split('='); // cookie value can contain "="
if(r) return r; // returns first found cookie
return n === name ? decodeURIComponent(val.join('=')) : r; // returns last found cookie (overwrites)
}, '');
}
You can run benchmarks by yourself here: https://www.measurethat.net/Benchmarks/Show/16012/5/getcookie-for-vs-forof-vs-indexof-vs-find-vs-reduce
setCookie() TypeScript function
Here is also my version of the function to set a cookie with encodeURIComponent, TypeScript, and SameSite option (which will be required by Firefox soon):
function setCookie(
name: string,
value: string = '',
days: number | false = false, // session length if not provided
path: string = '/', // provide an empty string '' to set for current path (managed by a browser)
sameSite: 'none' | 'lax' | 'strict' = 'lax', // required by Firefox
isSecure?: boolean
) {
let expires = '';
if (days) {
const date = new Date(
Date.now() + days * 24 * 60 * 60 * 1000
).toUTCString();
expires = '; expires=' + date;
}
const secure = isSecure || sameSite === 'none' ? `; Secure` : '';
const encodedValue = encodeURIComponent(value);
document.cookie = `${name}=${encodedValue}${expires}; path=${path}; SameSite=${sameSite}${secure}`;
}
Google Chrome Cookie Storage API
Thanks to #oncode answer it's worth mentioning that the Google Chrome team has proposed some standardization (finally! It's really ridiculous that we still don't have any commonly accepted API for cookies) with asynchronous Cookie Storage API (available in Google Chrome starting from version 87): https://wicg.github.io/cookie-store/
Unfortunately, it's still unofficial and isn't even under W3C consideration nor ES proposal: github.com/tc39/proposals
Such a shame we still don't have any standard API for cookies...
Fortunately, we have cookie-store polyfill for other browsers as npm package (gitHub), which is only 1.7kB Gzipped ;)

I use this object. Values are encoded, so it's necessary to consider it when reading or writing from server side.
cookie = (function() {
/**
* Sets a cookie value. seconds parameter is optional
*/
var set = function(name, value, seconds) {
var expires = seconds ? '; expires=' + new Date(new Date().getTime() + seconds * 1000).toGMTString() : '';
document.cookie = name + '=' + encodeURIComponent(value) + expires + '; path=/';
};
var map = function() {
var map = {};
var kvs = document.cookie.split('; ');
for (var i = 0; i < kvs.length; i++) {
var kv = kvs[i].split('=');
map[kv[0]] = decodeURIComponent(kv[1]);
}
return map;
};
var get = function(name) {
return map()[name];
};
var remove = function(name) {
set(name, '', -1);
};
return {
set: set,
get: get,
remove: remove,
map: map
};
})();

For reading simple querystrings, this one-liner might work for you in recent versions of JavaScript:
let cookies = Object.fromEntries(document.cookie.split(';').map(i=>i.trim().split('=')));
And now you have a JavaScript Object with keys and values.
For creating, you can try this one:
let cookieObject = {foo: 'bar', ping: "pong"}
Object.entries(cookieObject).map((e)=>`${e[0]}=${e[1]}`).join(';')

I've used js-cookie to success.
<script src="/path/to/js.cookie.js"></script>
<script>
Cookies.set('foo', 'bar');
Cookies.get('foo');
</script>

You can use my cookie ES module for get/set/remove cookie.
Usage:
In your head tag, include the following code:
<script src="https://raw.githack.com/anhr/cookieNodeJS/master/build/cookie.js"></script>
or
<script src="https://raw.githack.com/anhr/cookieNodeJS/master/build/cookie.min.js"></script>
Now you can use window.cookie for store user information in web pages.
cookie.isEnabled()
Is the cookie enabled in your web browser?
returns {boolean} true if cookie enabled.
Example
if ( cookie.isEnabled() )
console.log('cookie is enabled on your browser');
else
console.error('cookie is disabled on your browser');
cookie.set( name, value )
Set a cookie.
name: cookie name.
value: cookie value.
Example
cookie.set('age', 25);
cookie.get( name[, defaultValue] );
get a cookie.
name: cookie name.
defaultValue: cookie default value. Default is undefined.
returns cookie value or defaultValue if cookie was not found
Example
var age = cookie.get('age', 25);
cookie.remove( name );
Remove cookie.
name: cookie name.
Example
cookie.remove( 'age' );
Example of usage

I use the following functions, which I have written by taking the best I have found from various sources and weeded out some bugs or discrepancies.
The function setCookie does not have advanced options, just the simple stuff, but the code is easy to understand, which is always a plus:
function setCookie(name, value, daysToLive = 3650) { // 10 years default
let cookie = name + "=" + encodeURIComponent(value);
if (typeof daysToLive === "number") {
cookie += "; max-age=" + (daysToLive * 24 * 60 * 60);
document.cookie = cookie + ";path=/";
}
}
function getCookie(name) {
let cookieArr = document.cookie.split(";");
for (let i = 0; i < cookieArr.length; i++) {
let cookiePair = cookieArr[i].split("=");
if (name == cookiePair[0].trim()) {
return decodeURIComponent(cookiePair[1].trim());
}
}
return undefined;
}
function deleteCookie(name) {
setCookie(name, '', -1);
}

The chrome team has proposed a new way of managing cookies asynchronous with the Cookie Storage API (available in Google Chrome starting from version 87): https://wicg.github.io/cookie-store/
Use it already today with a polyfill for the other browsers: https://github.com/mkay581/cookie-store
// load polyfill
import 'cookie-store';
// set a cookie
await cookieStore.set('name', 'value');
// get a cookie
const savedValue = await cookieStore.get('name');

Very short ES6 functions using template literals. Be aware that you need to encode/decode the values by yourself but it'll work out of the box for simplier purposes like storing version numbers.
const getCookie = (cookieName) => {
return (document.cookie.match(`(^|;) *${cookieName}=([^;]*)`)||[])[2]
}
const setCookie = (cookieName, value, days=360, path='/') => {
let expires = (new Date(Date.now()+ days*86400*1000)).toUTCString();
document.cookie = `${cookieName}=${value};expires=${expires};path=${path};`
}
const deleteCookie = (cookieName) => {
document.cookie = `${cookieName}=;expires=Thu, 01 Jan 1970 00:00:01 GMT;path=/;`;
}

Simple way to read cookies in ES6.
function getCookies() {
var cookies = {};
for (let cookie of document.cookie.split('; ')) {
let [name, value] = cookie.split("=");
cookies[name] = decodeURIComponent(value);
}
console.dir(cookies);
}

Through a interface similar to sessionStorage and localStorage:
const cookieStorage = {
getItem: (key) {
const cookies = document.cookie.split(';')
.map(cookie => cookie.split('='))
.reduce(
(accumulation, [key, value]) => ({...accumulation, [key.trim()]: value}),
{}
)
return cookies[key]
},
setItem: (key, value) {
document.cookie = `${key}=${value}`
},
}
Its usage cookieStorage.setItem('', '') and cookieStorage.getItem('').

An improved version of the readCookie:
function readCookie( name )
{
var cookieParts = document.cookie.split( ';' )
, i = 0
, part
, part_data
, value
;
while( part = cookieParts[ i++ ] )
{
part_data = part.split( '=' );
if ( part_data.shift().replace(/\s/, '' ) === name )
{
value = part_data.shift();
break;
}
}
return value;
}
This should break as soon as you have found your cookie value and return its value. In my opinion very elegant with the double split.
The replace on the if-condition is a white space trim, to make sure it matches correctly

I have written simple cookieUtils, it has three functions for creating the cookie, reading the cookie and deleting the cookie.
var CookieUtils = {
createCookie: function (name, value, expireTime) {
expireTime = !!expireTime ? expireTime : (15 * 60 * 1000); // Default 15 min
var date = new Date();
date.setTime(date.getTime() + expireTime);
var expires = "; expires=" + date.toGMTString();
document.cookie = name + "=" + value + expires + "; path=/";
},
getCookie: function (name) {
var value = "; " + document.cookie;
var parts = value.split("; " + name + "=");
if (parts.length == 2) {
return parts.pop().split(";").shift();
}
},
deleteCookie: function(name) {
document.cookie = name +'=; Path=/; Expires=Thu, 01 Jan 1970 00:00:01 GMT;';
}
};

Here is the example from w3chools that was mentioned.
function setCookie(cname, cvalue, exdays) {
var d = new Date();
d.setTime(d.getTime() + (exdays*24*60*60*1000));
var expires = "expires="+ d.toUTCString();
document.cookie = cname + "=" + cvalue + ";" + expires + ";path=/";
}
function getCookie(cname) {
var name = cname + "=";
var decodedCookie = decodeURIComponent(document.cookie);
var ca = decodedCookie.split(';');
for(var i = 0; i <ca.length; i++) {
var c = ca[i];
while (c.charAt(0) == ' ') {
c = c.substring(1);
}
if (c.indexOf(name) == 0) {
return c.substring(name.length, c.length);
}
}
return "";
}

A simple read
var getCookie = function (name) {
var valueStart = document.cookie.indexOf(name + "=") + name.length + 1;
var valueEnd = document.cookie.indexOf(";", valueStart);
return document.cookie.slice(valueStart, valueEnd)
}

A cheeky and simple way of reading a cookie could be something like:
let username, id;
eval(document.cookie);
console.log(username + ", " + id); // John Doe, 123
This could be used if you know your cookie contains something like: username="John Doe"; id=123;. Note that a string would need quotes in the cookie. Not the recommended way probably, but works for testing/learning.

New value for cookie appended

This javascript code
function writeCookie(CookieName, CookieValue, CookieDuration) {
var expiration = new Date();
var now = new Date();
expiration.setTime(now.getTime() + (parseInt(CookieDuration) * 60000));
document.cookie = CookieName + '=' + escape(CookieValue) + '; expires=' + expiration.toGMTString() +
'; path=/';
}
function readCookie(CookieName) {
if (document.cookie.length > 0) {
var beginning = document.cookie.indexOf(CookieName + "=");
if (beginning != -1) {
beginning = beginning + CookieName.length + 1;
var ending = document.cookie.indexOf(";", beginning);
if (ending == -1) ending = document.cookie.length;
return unescape(document.cookie.substring(beginning, ending));
}
else {
return "";
}
}
return "";
}
var before = readCookie('totali');
var after = before + 1;
writeCookie('totali', after, 43200);
Should read cookie 'totali', add "1" to its value and then rewrite the new value.
The first time I run the code, cookie becomes "1", but the second time becomes "11", the third "111" and so on.
What could be the problem?

You are concatenating strings. Convert the value read from the cookie into a number before attempting to add it:
var after = parseInt(before) + 1;
But the problem is that the first time you read the cookie, the value is an empty string, and parseInt("") will be NaN. In this case, you have to check before you use it. This will assign 1 if the function returns an empty string, or the value stored in the cookie + 1 if not:
var after = (before.trim() == "") ? 1 : parseInt(before) + 1;
This assumes you never place anything other than a number in that totali cookie.
See http://jsfiddle.net/9rLZP/3/ (I changed the name of the cookie, so you can see the change without having to remove the previous cookie)

How do I pass in a cookie value returned from a javascript function to a JSON parameter field?

I have this kendo object and I'm concerned with this part of its configuration:
data: {
awardTitleId: e.data.AwardTitleId,
personId: X, //needs to be a variable
nameId: Y //needs to be a variable
}
I get the values for personId and nameId and store them into cookies.
function createCookie(name, value, days) {
if (days) {
var date = new Date();
date.setTime(date.getTime() + (days * 24 * 60 * 60 * 1000));
var expires = "; expires=" + date.toGMTString();
}
else expires = "";
document.cookie = name + "=" + value + expires + "; path=/";
}
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;
}
function eraseCookie(name) {
createCookie(name, "", -1);
}
The issue here is that for me to use the returned value from the "readCookie" function, it needs to be in a variable so I can do:
data: {
awardTitleId: e.data.AwardTitleId,
personId: variable1,
nameId: variable2
}
I can't do this:
data: {
awardTitleId: e.data.AwardTitleId,
personId: readCookie("personId"),
nameId: readCookie("nameId")
}
So my question is, how do I USE the values returned by these java script functions in my code? They sort of have to be "global variables" so that I can use it in other parts/events of the web page.
I tried declaring these variables at the top of my page, outside all functions but I keep getting 0's for the Ids.
The cookie functions ARE working, btw.
EDIT -
The function IS returning a value:

It looks like you're using jQuery so if you have a ready function you could set these values into your data object like this
var data: {
awardTitleId: e.data.AwardTitleId, //wherever you get this from
personId: null,
nameId: null
}
$(function(){
data.personId = readCookie("personId");
data.nameId = readCookie("nameId");
});
I'm not sure where your data object exactly lives, hopefully not at the global scope but you mention needing that globally earlier so that's where I've left it.
By assigning the personId and nameId in the ready function of the page then you will have them for the life of the page and won't need to continually get them from a cookie.

Retrieve Cookie Content

I'm trying tof ind a way to retrieve the content of a cookie in javascript.
Let's assume that the cookie is named "Google"
and lets also assume content of this cookie is just "blah"
I've been looking online and all I find are complex functions, and what I was wondering if there is a simple one line such code that retreives the value of the content in a cookie'
such as -
var myCookie = cookie.content('Google');
I don't want long parsers to check for various cookies or if the cookies have multiple value or whatever..Thanks!

QuirksMode has a very simple, but effective cookie script.
var Google = readCookie("Google"); // Google is now "blah"

Not exactly a simple one-line solution but close!
var results = document.cookie.match ( '(^|;) ?' + cookiename + '=([^;]*)(;|$)' );
if ( results ) myCookie = decodeURIComponent(results[2] ) ;

You'll have to parse the cookie jar yourself but it isn't that hard:
var name = 'the_cookie_you_want';
var value = null;
var cookies = document.cookie.split(/\s*;\s*/);
for(var i = 0; i < cookies.length; i++) {
if(cookies[i].substring(0, name.length + 1) == (name + '=')) {
value = decodeURIComponent(cookies[i].substring(name.length + 1));
break;
}
}

You can use document.cookie, or document.cookie.split(';') to get a full list of key/values.

In javascript all cookies are stored in a single string. THe cookies are separated by a ;
A possible function to read cookies is:
function readCookie(myCookieName)
{
if (document.cookie.length > 0)
{
var start = document.cookie.indexOf(myCookieName + "=");
if (start != -1)
{
start = start + myCookieName.length + 1;
var end = document.cookie.indexOf(";",start);
if (end == -1) end = document.cookie.length;
return unescape(document.cookie.substring(start ,end ));
}else{
return "";
}
}
return "";
}

javascript cookie, little help please

I am displaying a div on my site, and I want to only display this div 5 times that the user has visited my site. So after 5 times, it wont show the div anymore.
I can do it with cookies. But Im only familiar with PHP. Javascript isn't my strong side.
Does anybody have a short piece of code to set a cookie, increase it for every visit, and if value is greater than 5 then don't show the DIV anymore?
Thanks

let's say you have the variable visits in the cookies, you mainly use something similar to this
function getCookie(c_name)
{
if (document.cookie.length>0)
{
c_start=document.cookie.indexOf(c_name + "=");
if (c_start!=-1)
{
c_start=c_start + c_name.length+1;
c_end=document.cookie.indexOf(";",c_start);
if (c_end==-1) c_end=document.cookie.length;
return unescape(document.cookie.substring(c_start,c_end));
}
}
return "";
}
var visits = getCookie("visits_number");
if (visists > 5)
document.getElementById("your_div_name").setAttribute("style", "visibility: hidde");

Quirksmode has an article discussing cookies, which also includes three very handy helper functions (scroll down to the bottom). Read the article and all will become clear anyway.
Just remember that all information is stored as a string, and hence it is retrieved as a string. Therefore you should definitely be doing some manual type juggling before performing any operations on the data. See here:
var x = 1;
createCookie("myVar", x);
var newX = readCookie("myVar") + 1;
alert(newX); // "11"
// --- instead, do this: ---
var newX = parseInt(readCookie("myVar"), 10) + 1;

Nobody will have exactly the piece of code you are asking for, but it should be easy to compose it yourself, starting from these 2 necessary functions:
function createCookie(name,value,days) {
if (days) {
var date = new Date();
date.setTime(date.getTime()+(days*24*60*60*1000));
var expires = "; expires="+date.toGMTString();
}
else expires = "";
document.cookie = name+"="+value+expires+"; path=/";
}
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;
}