PHP SESSION VARIABLE
Session variable is a special type of array that holds information for an individual user with again unique session ID, like sending information from one web page to another or many pages using a unique identity by session ID for the individual user. It is used to persist (hold on) state information between page requests.
session variable automatically shuts down when PHP finishes executing a script, but we can shut down using the session_write_close() function.
Session Variable function’s list
| Function | Definition |
| session_start | It creates a session or resumes the current one based on the session ID identifier that passed through the GET or POST request. |
| session_status | Return the current status of the session variable. |
| session_id | It is used to get or set the session ID for the current session. |
| session_abort | It discards changes to the session array and finishes the session. |
| session_destroy | It destroys all data associated with the session variable. |
| session_reset | It reinitializes the session variable with its original value. |
| session_register | Register one or more global variables (defined outside the function) with the current session. |
| session_unset | Free all session variables that have been registered |
| session_write_close | It is used to write session data and end the session. |
What is $_SESSION in PHP
$_SESSION is an associative array containing session variables available to the current script. We can apply a session variable like this.
PHP Session Start
<?php
session_start(); //It should be mentioned first line of the script after PHP.
$_SESSION[‘variable_name’]=value;
?>
Destroying php session
A PHP session can be destroyed using the session_destroy() function. A single call to this function can destroy all session variables of the current running PHP script.
If we want to destroy a single session variable, we can use of unset () function to unset() session variable.
Here example of unset with PHP session
<?php
unset($_SESSION[‘counter’]);
?>
Creating and Working Session in PHP
How to use of session variable in PHP
Example of php session variable
with a login page and selecting fruit, and displaying it using a session
For example, we need to create three .php files
- login1.php
- trap.php
- display.php
Login1.php
<html>
<head<title>Login Page</title></head>
<body>
<form method=”post” action=”trap.php”>
User ID: <input type=”text” name=”uid”/><br/>
Password:<input type=”password” name=”pwd”/><br/>
<input type=”submit” name=”submit” value=”Login”>
</form>
</body>
</html>
trap.php
<?php
session_start();
$_SESSION[‘uid’]=$_POST[‘uid’];
$_SESSION[‘pwd’]=$_POST[‘pwd’];
if($_SESSION[‘uid’]==’php’ and $_SESSION[‘pwd’]==’1234′)
{
?>
<form method=”post” action=”display.php”>
Fruit choice for eat :<select name=”fruit”>
<option>Select</option>
<option>Mango</option>
<option>Banana</option>
<option>Orange</option>
</select>
<input type=”submit” name=”submit” value=”Select”/>
</form>
<?php
}
else
{
include(‘login1.php’);
echo “User or Password may be wrong!”;
}
?>
display.php
<?php
session_start();
$fruit=$_POST[‘fruit’];
echo $_SESSION[‘uid’].” you have selected $fruit”;
?>
