PHP - session_create_id() 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_create_id() function is used to create a new session id.

Syntax

session_create_id([$prefix]);

Parameters

Sr.No	Parameter & Description
1	prefix(Optional) This is a string value which can be used as a prefix to the created session id.

Return Values

This function returns an integer value representing the created session id.

PHP Version

This function was first introduced in PHP Version 7 and works in all the later versions.

Example 1

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

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

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

Id: v9qopnl27l534pbuuvd1tghm18

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

<?php
   if(isset($_POST['SubmitButton'])){ 
      //Starting the session	
      $id = session_create_id();	
      session_id($id);
      print("\n"."Id: ".$id);
      session_start();  
      $_SESSION['name'] = $_POST['name'];
      $_SESSION['age']  = $_POST['age'];	  
      session_commit();
   }
?>
<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 
            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
         //Session started
         session_start();
         print("Values from the session with id: ");
         print("br".session_id());
         echo "<br>";
         print($_SESSION['name']); 
         echo "<br>";
         print($_SESSION['age']);
      ?>   
   </body>   
</html>

This will produce the following output −

Values from the session with id: brb9t3gprjtl35ms4sm937hj7s30
Krishna
30

Example 3

You can pass optional prefix (string) to 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