How to add discount to cart total?

Question

I need to add discount according to number of product in cart and this discount will apply on total of cart. Is there any other option without use of coupons?

Answer 1

I prefer this way, more cleaner I think

// Hook before calculate fees
add_action('woocommerce_cart_calculate_fees' , 'add_custom_fees');

/**
 * Add custom fee if more than three article
 * @param WC_Cart $cart
 */
function add_custom_fees( WC_Cart $cart ){
    if( $cart->cart_contents_count < 3 ){
        return;
    }

    // Calculate the amount to reduce
    $discount = $cart->subtotal * 0.1;
    $cart->add_fee( 'You have more than 3 items in your cart, a 10% discount has been added.', -$discount);
}

Answer 2

This code should work:

add_action('woocommerce_before_cart_table', 'discount_when_produts_in_cart');
function discount_when_produts_in_cart( ) {
    global $woocommerce;
    if( $woocommerce->cart->cart_contents_count > 3 ) {
        $coupon_code = 'maryscode';
        if (!$woocommerce->cart->add_discount( sanitize_text_field( $coupon_code ))) {
            $woocommerce->show_messages();
        }
        echo '<div class="woocommerce_message"><strong>You have more than 3 items in your cart, a 10% discount has been added.';
    }
}

The above will apply the coupon "maryscode" to the cart if there are 4 or more products in the customers cart.

EDIT: Add the following to your css

.coupon 
{
    display: none !important;
}