In general, session refers to a frame of communication between two medium. A PHP session is used to store data on a server rather than the computer of the user. Session identifiers or SID is a unique number which is used to identify every user in a session based environment. The SID is used to link the user with his information on the server like posts, emails etc.
How are sessions better than cookies?
Below are different steps involved in PHP sessions:
Starting a PHP Session: The first step is to start up a session. After a session is started, session variables can be created to store information. The PHP session_start() function is used to begin a new session.It also creates a new session ID for the user.
Below is the PHP code to start a new session:
Storing Session Data: Session data in key-value pairs using the $_SESSION<> superglobal array.The stored data can be accessed during lifetime of a session.
Below is the PHP code to store a session with two session variables Rollnumber and Name:
Accessing Session Data: Data stored in sessions can be easily accessed by firstly calling session_start() and then by passing the corresponding key to the $_SESSION associative array.
The PHP code to access a session data with two session variables Rollnumber and Name is shown below:
The Name of the student is :Ajay The Roll number of the student is :11Destroying Certain Session Data: To delete only a certain session data,the unset feature can be used with the corresponding session variable in the $_SESSION associative array.
The PHP code to unset only the “Rollnumber” session variable from the associative session array:
Destroying Complete Session: The session_destroy() function is used to completely destroy a session. The session_destroy() function does not require any argument.