how to use a session php code example

Example 1: set php varibianle session

<?php 
  // Start the session
  session_start();
?>
<!DOCTYPE html>
<html>
  <body>
  <?php
    // Set session variables
    $_SESSION["color"]= "blue";
    $_SESSION["animal"]= "dog";
    echo "The session variable are set up.";
  ?>
  </body>
</html>

Example 2: php session

/*Sessions are stored on the server
Sessions are a way to carry data across multiple pages. 
Typically if we set a variable on one page, it wouldn't be available 
on the next page. This is where Sessions come in. Unlike cookies session
data is not stored on the user's computer. It is stored on the server. 
In order to use session variables you have to start a session. 
Every page, that you want to use that data in, you have to use 
session_start.

If you want to unset one of these sessions you can use session_unset

youcan destry the session with session_destroy
*/

<?php if(isset($_POST['submit']))
{ session_start(); // that will start the session
$_SESSION['name'] = htmlentities($_POST['name']);
$_SESSION['email'] = htmlentities($_POST['email']);
header('Location: page2.php'); } ?>
<!DOCTYPE html>
<html>
<head>
<title>PHP Sessions</title>
</head>
<body>
<form method="POST" action="<?php echo $server['PHP_SELF'];?>">
<input type="text" name="name" placeholder="Enter Name">
<br>
<input type="text" name="email" placeholder="Enter Email">
<br>
<input type="submit" name="submit" value="submit">
</form>
</body>
</html>