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.
I have a little function that makes URL arguments out of an object:
function MkArgs(o) {
var ret = '?';
for (var i in o) {
ret += i + '=' + escape(o[i]) + '&';
}
return ret.substr(0, ret.length - 1);
}
which I then can call like this:
MkArgs({
protocol: 'wsfederation',
realm: 'https://www.x.com/',
fedRes: 'Home/FederationResult',
context: '~/Home/FAQ',
version: '1.0',
callback: '?'
});
to produce the following:
?protocol=wsfederation&realm=https%3A//www.x.com/&fedRes=Home/FederationResult&context=%7E/Home/FAQ&version=1.0&callback=%3F
everything is fine except that I don't want the last argument escaped i.e. I want:
callback=?
instead of
callback=%3F
is there any way I can indicate that within the string? I tried '\?' but that doesn't do it and haven't found any references as to how to protect a piece of string from escaping...
e
The MkArgs function is your own; change it to include an escape mechanism. I would advise against using backslash, though. If this is just your own code, perhaps it would be enough to put in a hackish special case.
That's a pretty special case. Maybe you should change your function:
function MkArgs(o, isJSONP) {
var ret = '?';
for (var i in o) {
var val = o[i];
val = escape(val);
ret += i + '=' + val + '&';
}
return ret.substr(0, ret.length - 1) + isJSONP ? '&callback=?':'';
}
and call it:
MkArgs({
protocol: 'wsfederation',
realm: 'https://www.x.com/',
fedRes: 'Home/FederationResult',
context: '~/Home/FAQ',
version: '1.0'
}, true);
The escape or encodeURIComponent functions don't have any way of "skipping" certain characters. So, all you can do is to either avoid calling the encode function when you don't want to or replace the chars you don't want encoded, call encode and then put the original chars back again.
If you want to skip escaping the whole value for a particular key, you can just check for the particular keys that you don't want to escape and handle appropriately like this:
function MkArgs(o) {
var ret = '?';
for (var i in o) {
var val = o[i];
if (i != "callback") {
val = encodeURIComponent(val);
}
ret += i + '=' + val + '&';
}
return ret.substr(0, ret.length - 1);
}
If you want to skip just certain characters, then you can replace them with some unique sequence, escape and then put them back:
function MkArgs(o) {
var ret = '?';
for (var i in o) {
var val = o[i];
if (i == "callback") {
val = val.replace(/\?/, "--xx--"); // replace with unique sequence
val = encodeURIComponent(val);
val = val.replace(/--xx--/, "?"); // put orig characters back
} else {
val = encodeURIComponent(val);
}
ret += i + '=' + val + '&';
}
return ret.substr(0, ret.length - 1);
}
FYI, note I've switched to using encodeURIComponent() which is recommended over the deprecated escape() because escape() doesn't work for non-ascii characters.
thanks everyone for the replies. what I ended up doing was:
function MkArgs(o) {
var ret = '?';
for (var i in o) {
ret += i;
if (o[i]) ret += '=' + escape(o[i]);
ret += '&';
}
return ret.substr(0, ret.length - 1);
}
then calling it like:
MkArgs({
protocol: 'wsfederation',
realm: 'https://www.x.com/',
fedRes: 'Home/FederationResult',
context: '~/Home/FAQ',
version: '1.0',
'callback=?': null
});
that way I don't rely on the values but the keys to make the distinction. not really pretty but it's the best I could think of
function MkArgs(o) {
var ret = '?';
var lastEl = '';
for (var i in o) {
ret += i + '=' + escape(o[i]) + '&';
lastEl = o[i];
}
return ret.substr(0, ret.length - 1 - lastEl.length) + lastEl;
}
this works for the last element in the object.
EDIT: It seems that in a classic for in loop, javascript does not have a precise order in which it loops over the object props, so the above solution is not guaranteed to work.
In this case you have 2 solutions :
If you know which property you want to "protect" from escaping, you should check for that prop in the loop and specifically not escape it :
for (var i in o) {
if(i=="myProp")
// unescape
else
// escape
}
If you do not now the property, but you want only the last one added into the query, you can do something like this (after building the query) :
var q = MkArgs(o);
var parts = q.split('=');
var toUnescape = parts[parts.length-1];
q = q.substring(0,q.length - toUnescape.length) + unescape(toUnescape);
I have a string which is something like this :
a_href= "www.google.com/test_ref=abc";
I need to search for test_ref=abc in thisabove strinng and replace it with new value
var updated_test_ref = "xyz";
a_href ="www.google.com/test_ref=updated_test_ref"
i.e
www.google.com/test_ref=xyz.
How can we do this ?
EDIT:
test_ref value can be a URL link in itself something like http://google.com?param1=test1¶m2=test2. I need to capture complete value not till first &.
a_href = a_href.replace(/(test_ref=)[^\&]+/, '$1' + updated_test_ref);
Based on this discussion I have fixed the Chris function (problem with regex string!)
function updateUrlParameter(url, param, value){
var regex = new RegExp('('+param+'=)[^\&]+');
return url.replace( regex , '$1' + value);
}
Based on this discussion I have created a references function. enjoy
updateUrlParameter(url, param, value){
var regex = new RegExp("/([?|&]" + param + "=)[^\&]+/");
return url.replace(regex, '$1' + value);
}
I was searching for this solution for few hours and finally stumbled upon this question. I have tried all the solutions here. But there is still an issue while replacing specific param value in url.
Lets take a sample url like
http://google.com?param1=test1¶m2=test2&anotherparam1=test3
and the updated url should be like
http://google.com?param1=newtest¶m2=test2&anotherparam1=test3, where value of param1 is changed.
In this case, as #Panthro has pointed out, adding [?|&] before the querying string ensures that anotherparam1 is not replaced. But this solution also adds the '?' or '&' character to the matching string. So while replacing the matched characters, the '?' or '&' will also get replaced. You will not know exactly which character is replaced so you cannot append that character as well.
The solution is to match '?' or '&' as preceding characters only.
I have re-written the function of #Chris, fixing the issue with string and have added case insensitive argument.
updateUrlParameter(url, param, value){
var regex = new RegExp('(?<=[?|&])(' + param + '=)[^\&]+', 'i');
// return url.replace(regex, param + '=$1' + value);
return url.replace(regex, param + '=' + value);
}
Here (?<=[?|&]) means, the regex will match '?' or '&' char and will take the string that occurs after the specified character (looks behind the character). That means only param1=test1 substring will be matched and replaced.
I know this is a bit dirty code but I've achieved what I was looking for. It replaces the given query string or adds new one if it doesn't exist yet.
function updateUrlParameter(url, param, value) {
var index = url.indexOf("?");
if (index > 0) {
var u = url.substring(index + 1).split("&");
var params = new Array(u.length);
var p;
var found = false;
for (var i = 0; i < u.length; i++) {
params[i] = u[i].split("=");
if (params[i][0] === param) {
params[i][1] = value;
found = true;
}
}
if (!found) {
params.push(new Array(2));
params[params.length - 1][0] = param;
params[params.length - 1][1] = value;
}
var res = url.substring(0, index + 1) + params[0][0] + "=" + params[0][1];
for (var i = 1; i < params.length; i++) {
res += "&" + params[i][0] + "=" + params[i][1];
}
return res;
} else {
return url + "?" + param + "=" + value;
}
}
It will work when given regular URL addresses like:
updateUrlParameter('https://www.example.com/some.aspx?mid=1&id=2','id','5');
updateUrlParameter('https://www.example.com/?mid=1&id=2','id','5');
updateUrlParameter('https://www.example.com/some.aspx','id','5');
Please note It will NOT work only if any of the query string parameter name or value contains "=" and/or "&" chars. It will work just fine behind that.
*Java script code to find a specific query string and replace its value *
('input.letter').click(function () {
//0- prepare values
var qsTargeted = 'letter=' + this.value; //"letter=A";
var windowUrl = '';
var qskey = qsTargeted.split('=')[0];
var qsvalue = qsTargeted.split('=')[1];
//1- get row url
var originalURL = window.location.href;
//2- get query string part, and url
if (originalURL.split('?').length > 1) //qs is exists
{
windowUrl = originalURL.split('?')[0];
var qs = originalURL.split('?')[1];
//3- get list of query strings
var qsArray = qs.split('&');
var flag = false;
//4- try to find query string key
for (var i = 0; i < qsArray.length; i++) {
if (qsArray[i].split('=').length > 0) {
if (qskey == qsArray[i].split('=')[0]) {
//exists key
qsArray[i] = qskey + '=' + qsvalue;
flag = true;
break;
}
}
}
if (!flag)// //5- if exists modify,else add
{
qsArray.push(qsTargeted);
}
var finalQs = qsArray.join('&');
//6- prepare final url
window.location = windowUrl + '?' + finalQs;
}
else {
//6- prepare final url
//add query string
window.location = originalURL + '?' + qsTargeted;
}
})
});
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;
}