I want to move all members whose user role is empty to the default role. Is there a code about it?
Yes, first you can use wp_get_users_with_no_role()
function to get all users with no role (This function returns user ids). Then you can pass that user_id $u = new WP_User( $user_id );
and set the new role $u->set_role( 'subscriber' );
. Here you can also find list of user Roles and Capabilities.
Paste that in your theme functions.php
file.
add_action('init', function(){
$users = wp_get_users_with_no_role();
if( !empty($users) ){
foreach($users as $user_id) {
$u = new WP_User( $user_id );
$u->set_role( 'subscriber' );
}
}
}, 10);
This code isn't tested so let us know if that worked!