Cookies in Php

What Are Cookies?

Cookies are small pieces of data stored on the user's browser by websites they visit. These cookies serve various purposes, such as maintaining user sessions, remembering user preferences, tracking user behavior, and enabling personalized experiences. When a user revisits a website, the stored cookies are sent back to the server, allowing the website to recognize the user and customize their experience accordingly.

How Do Cookies Work?

The process of using cookies involves two main components: setting and retrieving cookies. Let's explore each step:

1. Setting Cookies:

In PHP, setting a cookie is a straightforward process. The `setcookie()` function is used for this purpose. It takes several parameters, including the cookie name, value, expiration time, domain, path, and secure flag. Here's a basic example of setting a cookie:

```php

// Set a cookie named "username" with the value "JohnDoe" that expires in one week

setcookie("username", "Champak Roy", time() + (7 * 24 * 3600));

```

2. Retrieving Cookies:

Once the cookie is set, PHP can retrieve its value on subsequent page requests using the `$_COOKIE` superglobal array. For example:

```php

// Check if the cookie "username" exists and display its value

if (isset($_COOKIE['username'])) {

echo "Welcome back, " . $_COOKIE['username'] . "!";

} else {

echo "Welcome, guest!";