What are common reasons for cookies not being stored online when using PHP?

Common reasons for cookies not being stored online when using PHP could be due to incorrect settings in the `php.ini` file, browser settings blocking cookies, or improper coding in the PHP script. To solve this issue, make sure that cookies are enabled in the browser, check the `php.ini` file for the correct settings related to cookies, and ensure that the PHP script is correctly setting the cookie parameters.

// Set a cookie with a name, value, expiration time, and path
setcookie("example_cookie", "example_value", time() + 3600, "/");