Use the isset()
function upon the superglobal $_COOKIE
variable to check if a cookie is set.
Example:
// PHP <7.0
if (isset($_COOKIE['user'])) {
// true, cookie is set
echo 'User is ' . $_COOKIE['user'];
else {
// false, cookie is not set
echo 'User is not logged in';
}
// PHP 7.0+
echo 'User is ' . $_COOKIE['user'] ?? 'User is not logged in';