This  code snippet let you display you wordpress user’s ID number on Post or Page.

<?php function Display_user_ID_for_Me() {
<pre>global $current_user;
$current_user = wp_get_current_user();
return $current_user->ID;
}
add_shortcode('DisplayUserID', 'Display_user_ID_for_Me');
?>

How  To Use:

1. Copy and Paste this code in functions.php file of your wordpress theme.

2. Use  [DisplayUserID] this shortcode the display User’s ID number on Post or Page.