Uses of cookies

Cookies can be used for different purpose:

• Store data like (font size, color, element properties, theme, or anything about a particular user, etc.)
• Track something like (page count, percentage, behavior, etc.)
• Store username or numbers (to validate the user)

Set Cookie

We can create a cookie using PHP setcookie(). This function needs mainly 3 parameters to create a cookie, name, value, and expiration time.

$cookie_val = 'atcodex'; //variable 
setcookie("websiteName", $cookie_val, time()+3600); //cookie name, value & time (1 hour)

Note: The setcookie() function must appear before the <html> tag.

If you run the code, it should create a cookie named “websiteName” with its value “atcodex” on the user computer, cookies expire time has set 1 hour so after an hour it will automatically be expired. In the same way we can set multiple cookies according to our requirements in website.

You can set more advanced parameters, which include path, domain, secure, httponly. setcookie(NAME, VALUE, EXPIRE, PATH, DOMAIN, SECURE, HTTPONLY)

$cookie_val = 'atcodex'; //variable 
setcookie("websiteName", $cookie_val, time()+3600, '/', 'atcodex.com', true, true);

We have set ‘/’ in the path which means that cookies will be available in the entire domain. You can set cookies in ‘/folderName’ and then the cookie will available only in that folder and its sub-directories.

Retrieve Cookie Value

After setting the cookie value we can easily retrieve the cookie’s value on any page within the website using  $_COOKIE . The below code will show the cookie’s value in the browser.

echo 'Your Website Name Is ' . $_COOKIE['websiteName'];

Once cookies stored in the browser, it remain in the borswer till the expiration date or user deliberatly clear it in broswer setting. But if you want to delete cookies you do with just simple code shown in belwo example.

Delete a Cookie

To delete the stored cookie, just set the expiration date to negative.

setcookie("websiteName", "", time()-3600); //expiration time set to one hour ago

When you run this code, it will set the cookie to before time which triggers the browser cookie removal mechanism, which instantly removes cookie from the browser.

Updating Cookie in PHP

To update/modify a cookie value, simply just set its value again. like if we want to update the ‘websiteName‘, just change the name parameter using setcookie() method again.

$cookie_val = 'atcodex2'; //variable 
setcookie("websiteName", $cookie_val, time()+3600); //cookie name, value & time (1 hour)

Delete all cookies php

if we want to delete all the cookies at one go then just run the below code, it will unset all of the cookies on your domain

// unset cookies all at one go
if (isset($_SERVER['HTTP_COOKIE'])) {
    $cookies = explode(';', $_SERVER['HTTP_COOKIE']);
    foreach($cookies as $cookie) {
        $parts = explode('=', $cookie);
        $name = trim($parts[0]);
        setcookie($name, '', time()-3600);
        setcookie($name, '', time()-3600, '/');
    }
}

How to store Array and JSON in Cookie

Sometimes we need to store array in a cookie, for that, we need to define all the value in the array and just use json_encode to encode that array in JSON and store in a cookie.

Store JSON value in Cookie

$arrayData=array(
    'beginner',
    'Inertmediate',
    'Expert'    
);
setcookie('cookieData', json_encode($arrayData));

Store array value in Cookie

setcookie ("atcodex[name]", $name);
setcookie ("atcodex[city]", $city);
setcookie ("atcodex[state]", $state);
setcookie ("atcodex[zip]", $zip);

How to Retrieve Array and JSON from Cookie

Get value of stored JSON

$arrayData = json_decode($_COOKIE['cookieData']);

Get value of stored array

$_COOKIE['atcodex']['name']
$_COOKIE['atcodex']['city']
$_COOKIE['atcodex']['state']
$_COOKIE['atcodex']['zip']

The post How to Create, Access and Delete Cookies in PHP appeared first on AtCodex: Empowering Your Financial Journey & Personal Well-Being.