How to check user role?

Looking around Google for a few minutes yielded several promising results.

Here’s a more detailed one adapted from a snippet on The Code Collective:

function get_user_roles( $user_id ) {
    $user_roles = [];

    $user = get_userdata( $user_id );
    $capabilities = $user->{$wpdb->prefix . 'capabilities'};

    if ( !isset( $wp_roles ) ) {
        $wp_roles = new WP_Roles();

        foreach ( $wp_roles->role_names as $role => $name ) {

            if ( array_key_exists( $role, $capabilities ) )
                $user_roles[] = $role;
        }
    }

    return $user_roles;
}

This will return an array of the user passed in as $user_id.