PHP - session_name() Function

Definition and Usage

Sessions or session handling is a way to make the data available across various pages of a web application. The session_name() function is used to name the current session or, retrieve the name of the session.

Syntax

session_name([$name]);

Parameters

Sr.No	Parameter & Description
1	name(Optional) This is a string value representing the name of the session, if you want to set name of the session using this method.

Return Values

If you haven’t passed any parameters this function returns a string value representing the name of the current session. If you have passed a string value to set the name to the current session using this function returns the name of the old session.

PHP Version

This function was first introduced in PHP Version 4 and works in all the later versions.

Example 1

Following example demonstrates the usage of the session_name() function.

<html>   
   <head>
      <title>Setting up a PHP session</title>
   </head>   
   <body>
      <?php  
         //Starting the session
         session_start();   
         $name = session_name();
         print("Session Name: ".$name);
      ?>
   </body>   
</html>

One executing the above html file it will display the following message −

Session Name: PHPSESSID

Example 2

Following is another example of this function, in here we have two pages from the same application in the same session −

session_page1.htm

html>
   <body>
      <form action="#" method="post">
         <label for="fname">Enter the values click Submit and click on Next</label>
         <br><br><label for="fname">Name:</label>
         <input type="text" id="name" name="name"><br><br>
         <label for="lname">Age:</label>
         <input type="text" id="age" name="age"><br><br>           
         <input type="submit" name="SubmitButton"/>
         <?php 
            if(isset($_POST['SubmitButton'])){ 
               //Setting the session name	
               session_name("my_session");
               //Starting the session	  
               session_start();  
               $_SESSION['name'] = $_POST['name'];
               $_SESSION['age']  = $_POST['age'];	  
               print("<br><br>Session name: ".session_name());
            }
            echo '<br><br><a href="session_page2.htm">Next</a>';
         ?>
      </form>
   </body>
</html>

This will produce the following output −

Once you press submit the page will be like −

On clicking on Next the following file is executed.

session_page2.htm

<html>   
   <head>
      <title>Second Page</title>
   </head>
   <body>
      <?php
         //Changing the session name again
         $s_name = session_name();
     
         //Starting a Session
         session_start();
        
         print($_SESSION['name']); 
         echo "<br><br>";
         print($_SESSION['age']); 	  
         echo "<br><br>";
         print("Previous Session Name: ".$s_name);
      ?>   
   </body>   
</html>

This will produce the following output −

Krishna
30
Previous Session Name: PHPSESSID

Example 3

You can set custom session name by using this function as shown below −

<html>   
   <head>
      <title>Setting up a PHP session</title>
   </head>   
   <body>
      <?php  
         //Starting the session
         session_start();   
         $id = session_create_id("test-");
         print("Id: ".$id);
      ?>
   </body>   
</html>

One executing the above html file it will display the following message.

Id: test-es6j8171lluesjrokpvqqb4b4d

php_function_reference.htm