Wordpress get user id by email

Question

I need to look up a user id by the email address they created their account with. Normally I would use:

<?php $user_ID = get_current_user_id(); ?> 

But in this case, the user has not been signed in yet.

Answer 1

Found a quick way to do it:

$user = get_user_by( 'email', '[email protected]' );
$userId = $user->ID;