How to hide the admin bar?

In this tutorial you will learn now to hide the admin bar when logged in. This can be useful if you have a membership site and you don’t want to give users the ability to log out.

To hide admin bar for all users

/* Disable WordPress Admin Bar for all users */
add_filter( 'show_admin_bar', '__return_false' );

To hide the admin bar for certain user levels.
NOTE: Remember to change the user levels at the bottom of the code. This particular code hides the admin bar for the ‘customer‘ role and the ‘subscriber‘ role.

function tf_check_user_role( $roles ) {
    /*@ Check user logged-in */
    if ( is_user_logged_in() ) :
        /*@ Get current logged-in user data */
        $user = wp_get_current_user();
        /*@ Fetch only roles */
        $currentUserRoles = $user->roles;
        /*@ Intersect both array to check any matching value */
        $isMatching = array_intersect( $currentUserRoles, $roles);
        $response = false;
        /*@ If any role matched then return true */
        if ( !empty($isMatching) ) :
            $response = true;        
        endif;
        return $response;
    endif;
}
$roles = [ 'customer', 'subscriber' ];
if ( tf_check_user_role($roles) ) :
    add_filter('show_admin_bar', '__return_false');
endif;

If logging out is essential, you can use the yoursite.com\wp-admin address to get back to the dashboard.

PRO TIP:
To see what your customer sees, you can utilise a User Role Switching Plugin such as
https://wordpress.org/plugins/wp-user-role-switcher/