validity check for html code example

Example 1: alert in php

echo '<script>alert("Message")</script>';

Example 2: show alert in php

echo '<script language="javascript">alert("juas");</script>';

Example 3: php sessions

<?php
  	// Start new or resume existing session.
  	session_start();
	
	// Add values to the session.
	$_SESSION['item_name'] = 'value'; // string
	$_SESSION['item_name'] = 0; // int
	$_SESSION['item_name'] = 0.0; // float

	// Get session values.
	$value = $_SESSION['item_name'];
?>

Example 4: create session in php

<?php 
  // Start the session
  session_start();

  // Set session variables
  $_SESSION["color"]= "blue";
  $_SESSION["animal"]= "dog";
  echo "The session variable are set up.";
?>