In Wordpress Retrieves the information pertaining to the currently logged in user

<?php global $current_user;
      get_currentuserinfo();

      echo 'Username: ' . $current_user->user_login . "\n";
      echo 'User email: ' . $current_user->user_email . "\n";
      echo 'User first name: ' . $current_user->user_firstname . "\n";
      echo 'User last name: ' . $current_user->user_lastname . "\n";
      echo 'User display name: ' . $current_user->display_name . "\n";
      echo 'User ID: ' . $current_user->ID . "\n";
?>