storing multiple values of a variable in cookie and comparing - php

Question

How can i store multiple values for a variable in cookie using php, for example
$id = 1,2,4,5
Then how can i compare the stored values with a variable? for example, $new_id=4, i want to check if $new_id value exists in the stored values of $id in cookie.
Thanks for help and have a nice day.

Answer 1

You can store arbitrary strings in cookie elements, so a serialized array should work. Example:
// To store:
$ids = array(1, 2, 3, 4);
setcookie('ids', serialize($ids));
// To retrieve:
$serialized = $_COOKIE['ids'];
$ids = unserialize($serialized);
// sanity check: $ids needs to be an array.
assert(is_array($ids));
// Now let's check:
if (in_array(4, $ids)) {
// Yes, it's here.
}
A few caveats though:
The cookie is completely in the hands of the client, and cookie values should never be trusted. Treat them just like you would treat query string parameters or POST data.
Cookies offer very limited storage (IIRC, the standard gives you 4096 bytes to work with).
With these in mind, it might be a better idea to store the array in $_SESSION instead - this will give you virtually unlimited storage, and the only way for the client application to fiddle with the values is through your code.

Answer 2

Try with following snippet.
// do Stuff to retrieve value of $id from cookie.
// explode variable to array
$idArr = explode(',' , $id);
// check existence of new_id in cookie variable.
if(in_array($new_id , $idArr)){
// new_id exist in cookie variable
}
Hope this will help
Thanks!
Hussain.

Answer 3

to use the multiple value you can use the array and then to store it you can serialize ( and unserialize) the array.
To create array: $array = array(1,2,3,4);
To compare: if (in_array(2,$array)) echo "Yep";
To serialize the data to be stored: $store = serialize($array);
Ten you will be able to create the cookie with $store data and then use unserialize($store) to reconvert data in array.
Serialize Manual

Answer 4

Store array in cookie and then compare them

Answer 5

Here is one out of many solutions (syntax may contain errors):
// Create an array with the values you want to store in the cookie
$id = array(1, 2, 3, 4);
// Create cookie
set_cookie('id', implode(',', $id));
// Get cookie
$id = explode(',', $_COOKIE['id']);
// Test value
if(in_array($newId, $id) === true) {
// Value is in the array
}
Restrictions:
The values stored in $id cannot include commas, choose another separator if you need to store commas