How can PHP developers effectively manage and manipulate user cookies for personalized experiences?

To effectively manage and manipulate user cookies for personalized experiences, PHP developers can set, retrieve, and modify cookies using PHP's built-in functions like setcookie() and $_COOKIE. By storing user-specific data in cookies, developers can personalize user experiences by remembering preferences, login status, or shopping cart items.

// Set a cookie with a user-specific value
setcookie("user_id", "12345", time() + 3600, "/");

// Retrieve and use the cookie value
$user_id = $_COOKIE["user_id"];
echo "Welcome back, User ID: " . $user_id;

// Modify an existing cookie
setcookie("user_id", "54321", time() + 3600, "/");