Add css class to string

I’m trying to add css classes, so that each status (active, pending, canceled) has its own css class on the frontend. Please help.

function rcp_get_status_label( $status = '' ) {

    static $labels = null;

    // Array of status labels
    if ( null === $labels ) {
        $labels = array(

            // General
            'active'    => __( 'Active', 'rcp'),
            'inactive'  => __( 'Inactive', 'rcp' ),
            'pending'   => __( 'Pending', 'rcp' ),

            // Memberships
            'cancelled' => __( 'Cancelled',  'rcp' ),
            'expired'   => __( 'Expired',   'rcp' ),
            'free'      => __( 'Free',    'rcp' ), // deprecated

            // Payments
            'abandoned' => __( 'Abandoned', 'rcp' ),
            'complete'  => __( 'Complete', 'rcp' ),
            'failed'    => __( 'Failed', 'rcp' ),
            'refunded'  => __( 'Refunded', 'rcp' ),
            'new'       => __( 'New', 'rcp' ),
            'renewal'   => __( 'Renewal', 'rcp' ),
            'upgrade'   => __( 'Upgrade', 'rcp' ),
            'downgrade' => __( 'Downgrade', 'rcp' ),

            // Discount Codes
            'disabled'  => __( 'Disabled', 'rcp' ),
        );
    }

                <td data-th="<?php esc_attr_e( 'Status', 'rcp' ); ?>">
                    <?php rcp_print_membership_status( $membership->get_id() ); ?>
                </td>