How to show subtotal after applying and deducting coupon discount.

functions.php

<?php

/**
* Show the cart subtotal after coupon discount -- By Darshan Gada
* @uses coupon_discount()
*/
function update_woocommerce_cart_subtotal( $cart_subtotal, $compound, $obj ){
    $t = 0;
    foreach ( $obj->cart_contents as $key => $product ) :
        $product_price = $product['line_total'];
        foreach ( WC()->cart->get_coupons('order') as $code => $coupon ) :
            if( in_array( $product['product_id'], $coupon->product_ids )
            || in_array( $coupon->discount_type, array( 'percent_cart', 'fixed_cart' ) ) ):
                $product_price = coupon_discount( $product['line_total'], $coupon->discount_type, $coupon->amount );
            endif;
        endforeach;
        $t += $product_price;
    endforeach;
    return ( $t > 0 ) ? sprintf( '%s', wc_price( $t ) ) : $cart_subtotal ;
}

function coupon_discount( $price, $type, $amount ){
    switch( $type ){
        case 'percent_product':
            $newprice = $price * ( 1 - $amount/100 );
            break;
        case 'fixed_product':
            $newprice = $price - $amount;
            break;
        case 'percent_cart':
            $newprice = $price * ( 1 - $amount/100 );
            break;
        case 'fixed_cart':
            $newprice = $price - $amount;
            break;
        default:
            $newprice = $price;
    }
    return $newprice;
}

add_filter( 'woocommerce_cart_subtotal', 'update_woocommerce_cart_subtotal', 99, 3 );


?>