PHP/Cookie Session/Session Variables Delete

Delete session variable

<?php
   session_start();
   $_SESSION["username"] = "Joe";
   echo "Your username is: ".$_SESSION["username"].".<br />";
   
   /* Delete the session variable. */
   unset($_SESSION["username"]);
   /* Demonstrate that session variable is indeed gone. */
   echo "Username now set to: ".$_SESSION["username"].".";
?>

Deleting Existing Session Variables

<?php
  session_start () ;
  session_register ( "A" ) ;
  session_register ( "B" ) ;
  session_register ( "C" ) ;
  
  $A = "AAA";
  $B = "BBB";
  $C = "CCC";
  $result = session_destroy () ;
  if ($result=1) {
     echo "The session is destroyed! " , "\n " ;
  } else {
     echo "The session could not be destroyed. " , " \n" ;
  }
  
  echo $pop;
?>