Storing PHP Arrays in Cookies

In PHP, arrays can be stored in cookies for easy retrieval on subsequent requests. However, it is crucial to consider the security implications and use proper serialization techniques.

Serialization Options

To convert the array into a cookie-compatible format, you can choose from the following methods:

JSON

setcookie('your_cookie_name', json_encode($info), time() 3600);

implode/explode

This method is effective for arrays consisting solely of integers:

$encodedArray = implode(',', $info);
setcookie('your_cookie_name', $encodedArray, time() 3600);

Caution: Avoid using serialize/unserialize due to potential security risks.

Alternative Method: Non-Serialization

An alternative option is to store array elements individually in separate cookies:

setcookie('my_array[0]', 'value1' , time() 3600);
setcookie('my_array[1]', 'value2' , time() 3600);
setcookie('my_array[2]', 'value3' , time() 3600);

When you print the $_COOKIE variable, it will contain the array as follows:

echo '<pre>';
print_r( $_COOKIE );
die();

Array
(   
    [my_array] => Array
        (
            [0] => value1
            [1] => value2
            [2] => value3
        )

)

This non-serialization approach is a documented PHP feature that stores cookie names as array names, allowing retrieval as arrays in PHP scripts.