PHP Sessions
PHP Sessions
In PHP, a session is a way to store information on the server that can be accessed across multiple requests by the same user. Sessions are typically used to store user information, such as login credentials or shopping cart items, as the user navigates your website.
Here’s an example of how to use sessions in PHP:
Starting a session:
session_start();
In this example, we’re using the session_start() function to start a new session or resume an existing session.
Setting session variables:
$_SESSION["username"] = "JohnDoe";
In this example, we’re using the $_SESSION superglobal to set a session variable named “username” with a value of “JohnDoe”.
Retrieving session variables:
if(isset($_SESSION["username"])) {
echo "Welcome " . $_SESSION["username"];
} else {
echo "Please log in";
}
In this example, we’re using the isset() function to check if the “username” session variable is set. If the variable is set, we display a welcome message that includes the value of the variable. If the variable is not set, we display a message asking the user to log in.
Destroying a session:
session_destroy();
In this example, we’re using the session_destroy() function to destroy the current session and delete all session data.
Note that session data is stored on the server, not on the user’s computer, so it is generally more secure than using cookies. However, sessions have a default timeout period and can be invalidated if the user clears their browser cache or cookies, so they should not be used for storing critical data.