destroy session php

PHP
session_destroy(); // To delete whole session
// OR
unset($_SESSION['myVar']); // To delete a session var<?php
   unset($_SESSION['counter']);
?><?php 
 session_start(); // start session
 session_destroy();  // Delete whole session
// OR
unset($_SESSION['username']); // delete any specific session only
?><?php
// Destroy the currently active session.
session_destroy();
?><?php
session_destroy();
?>

<?php
   session_start();
   $_SESSION['var'];
?>
Source

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