PHP Snippet 1:
function woocommerce_maybe_add_multiple_products_to_cart() {
// Make sure WC is installed, and add-to-cart qauery arg exists, and contains at least one comma.
if ( ! class_exists( 'WC_Form_Handler' ) || empty( $_REQUEST['add-to-cart'] ) || false === strpos( $_REQUEST['add-to-cart'], ',' ) ) {
    return;
}
// Remove WooCommerce's hook, as it's useless (doesn't handle multiple products).
remove_action( 'wp_loaded', array( 'WC_Form_Handler', 'add_to_cart_action' ), 20 );
$product_ids = explode( ',', $_REQUEST['add-to-cart'] );
$count       = count( $product_ids );
$number      = 0;
foreach ( $product_ids as $product_id ) {
    if ( ++$number === $count ) {
        // Ok, final item, let's send it back to woocommerce's add_to_cart_action method for handling.
        $_REQUEST['add-to-cart'] = $product_id;
        return WC_Form_Handler::add_to_cart_action();
    }
    $product_id        = apply_filters( 'woocommerce_add_to_cart_product_id', absint( $product_id ) );
    $was_added_to_cart = false;
    $adding_to_cart    = wc_get_product( $product_id );
    if ( ! $adding_to_cart ) {
        continue;
    }
    $add_to_cart_handler = apply_filters( 'woocommerce_add_to_cart_handler', $adding_to_cart->product_type, $adding_to_cart );
    /*
     * Sorry.. if you want non-simple products, you're on your own.
     *
     * Related: WooCommerce has set the following methods as private:
     * WC_Form_Handler::add_to_cart_handler_variable(),
     * WC_Form_Handler::add_to_cart_handler_grouped(),
     * WC_Form_Handler::add_to_cart_handler_simple()
     *
     * Why you gotta be like that WooCommerce?
     */
    if ( 'simple' !== $add_to_cart_handler ) {
        continue;
    }
    // For now, quantity applies to all products.. This could be changed easily enough, but I didn't need this feature.
    $quantity          = empty( $_REQUEST['quantity'] ) ? 1 : wc_stock_amount( $_REQUEST['quantity'] );
    $passed_validation = apply_filters( 'woocommerce_add_to_cart_validation', true, $product_id, $quantity );
    if ( $passed_validation && false !== WC()->cart->add_to_cart( $product_id, $quantity ) ) {
        wc_add_to_cart_message( array( $product_id => $quantity ), true );
    }
}
}
 // Fire before the WC_Form_Handler::add_to_cart_action callback.
 add_action( 'wp_loaded',        'woocommerce_maybe_add_multiple_products_to_cart', 15 );
PHP Snippet 2:
    // adds support for multi add to cart for 3rd party cart plugin
function woocommerce_maybe_add_multiple_products_to_cart() {
    // Make sure WC is installed, and add-to-cart qauery arg exists, and contains at least one comma.
    if ( ! class_exists( 'WC_Form_Handler' ) || empty( $_REQUEST['add-to-cart'] ) || false === strpos( $_REQUEST['add-to-cart'], ',' ) ) {
        return;
    }
    // Remove WooCommerce's hook, as it's useless (doesn't handle multiple products).
    remove_action( 'wp_loaded', array( 'WC_Form_Handler', 'add_to_cart_action' ), 20 );
    $product_ids = explode( ',', $_REQUEST['add-to-cart'] );
    $count       = count( $product_ids );
    $number      = 0;
    foreach ( $product_ids as $product_id ) {
        if ( ++$number === $count ) {
            // Ok, final item, let's send it back to woocommerce's add_to_cart_action method for handling.
            $_REQUEST['add-to-cart'] = $product_id;
            return WC_Form_Handler::add_to_cart_action();
        }
        $product_id        = apply_filters( 'woocommerce_add_to_cart_product_id', absint( $product_id ) );
        $was_added_to_cart = false;
        $adding_to_cart    = wc_get_product( $product_id );
        if ( ! $adding_to_cart ) {
            continue;
        }
        // only works for simple atm
        if ( $adding_to_cart->is_type( 'simple' ) ) {
            // quantity applies to all products atm
            $quantity          = empty( $_REQUEST['quantity'] ) ? 1 : wc_stock_amount( $_REQUEST['quantity'] );
            $passed_validation = apply_filters( 'woocommerce_add_to_cart_validation', true, $product_id, $quantity );
            if ( $passed_validation && false !== WC()->cart->add_to_cart( $product_id, $quantity ) ) {
                wc_add_to_cart_message( array( $product_id => $quantity ), true );
            }
        }
    }
}
add_action( 'wp_loaded', 'woocommerce_maybe_add_multiple_products_to_cart', 15 );
PHP Snippet 3:
function woocommerce_maybe_add_multiple_products_to_cart() {
  // Make sure WC is installed, and add-to-cart qauery arg exists, and contains at least one comma.
  if ( ! class_exists( 'WC_Form_Handler' ) || empty( $_REQUEST['add-to-cart'] ) || false === strpos( $_REQUEST['add-to-cart'], ',' ) ) {
      return;
  }
  remove_action( 'wp_loaded', array( 'WC_Form_Handler', 'add_to_cart_action' ), 20 );
  $product_ids = explode( ',', $_REQUEST['add-to-cart'] );
  $count       = count( $product_ids );
  $number      = 0;
  foreach ( $product_ids as $product_id ) {
      if ( ++$number === $count ) {
          // Ok, final item, let's send it back to woocommerce's add_to_cart_action method for handling.
          $_REQUEST['add-to-cart'] = $product_id;
          return WC_Form_Handler::add_to_cart_action();
      }
      $product_id        = apply_filters( 'woocommerce_add_to_cart_product_id', absint( $product_id ) );
      $was_added_to_cart = false;
      $adding_to_cart    = wc_get_product( $product_id );
      if ( ! $adding_to_cart ) {
          continue;
      }
      if ( $adding_to_cart->is_type( 'simple' ) ) {
          // quantity applies to all products atm
          $quantity          = empty( $_REQUEST['quantity'] ) ? 1 : wc_stock_amount( $_REQUEST['quantity'] );
          $passed_validation = apply_filters( 'woocommerce_add_to_cart_validation', true, $product_id, $quantity );
          if ( $passed_validation && false !== WC()->cart->add_to_cart( $product_id, $quantity ) ) {
              wc_add_to_cart_message( array( $product_id => $quantity ), true );
          }
      } else {
          $variation_id       = empty( $_REQUEST['variation_id'] ) ? '' : absint( wp_unslash( $_REQUEST['variation_id'] ) );
          $quantity           = empty( $_REQUEST['quantity'] ) ? 1 : wc_stock_amount( wp_unslash( $_REQUEST['quantity'] ) ); // WPCS: sanitization ok.
          $missing_attributes = array();
          $variations         = array();
          $adding_to_cart     = wc_get_product( $product_id );
          if ( ! $adding_to_cart ) {
            continue;
          }
          // If the $product_id was in fact a variation ID, update the variables.
          if ( $adding_to_cart->is_type( 'variation' ) ) {
            $variation_id   = $product_id;
            $product_id     = $adding_to_cart->get_parent_id();
            $adding_to_cart = wc_get_product( $product_id );
            if ( ! $adding_to_cart ) {
              continue;
            }
          }
          // Gather posted attributes.
          $posted_attributes = array();
          foreach ( $adding_to_cart->get_attributes() as $attribute ) {
            if ( ! $attribute['is_variation'] ) {
              continue;
            }
            $attribute_key = 'attribute_' . sanitize_title( $attribute['name'] );
            if ( isset( $_REQUEST[ $attribute_key ] ) ) {
              if ( $attribute['is_taxonomy'] ) {
                // Don't use wc_clean as it destroys sanitized characters.
                $value = sanitize_title( wp_unslash( $_REQUEST[ $attribute_key ] ) );
              } else {
                $value = html_entity_decode( wc_clean( wp_unslash( $_REQUEST[ $attribute_key ] ) ), ENT_QUOTES, get_bloginfo( 'charset' ) ); // WPCS: sanitization ok.
              }
              $posted_attributes[ $attribute_key ] = $value;
            }
          }
          // If no variation ID is set, attempt to get a variation ID from posted attributes.
          if ( empty( $variation_id ) ) {
            $data_store   = WC_Data_Store::load( 'product' );
            $variation_id = $data_store->find_matching_product_variation( $adding_to_cart, $posted_attributes );
          }
          // Do we have a variation ID?
          if ( empty( $variation_id ) ) {
            throw new Exception( __( 'Please choose product options…', 'woocommerce' ) );
          }
          // Check the data we have is valid.
          $variation_data = wc_get_product_variation_attributes( $variation_id );
          foreach ( $adding_to_cart->get_attributes() as $attribute ) {
            if ( ! $attribute['is_variation'] ) {
              continue;
            }
            // Get valid value from variation data.
            $attribute_key = 'attribute_' . sanitize_title( $attribute['name'] );
            $valid_value   = isset( $variation_data[ $attribute_key ] ) ? $variation_data[ $attribute_key ]: '';
            /**
             * If the attribute value was posted, check if it's valid.
             *
             * If no attribute was posted, only error if the variation has an 'any' attribute which requires a value.
             */
            if ( isset( $posted_attributes[ $attribute_key ] ) ) {
              $value = $posted_attributes[ $attribute_key ];
              // Allow if valid or show error.
              if ( $valid_value === $value ) {
                $variations[ $attribute_key ] = $value;
              } elseif ( '' === $valid_value && in_array( $value, $attribute->get_slugs() ) ) {
                // If valid values are empty, this is an 'any' variation so get all possible values.
                $variations[ $attribute_key ] = $value;
              } else {
                throw new Exception( sprintf( __( 'Invalid value posted for %s', 'woocommerce' ), wc_attribute_label( $attribute['name'] ) ) );
              }
            } elseif ( '' === $valid_value ) {
              $missing_attributes[] = wc_attribute_label( $attribute['name'] );
            }
          }
          if ( ! empty( $missing_attributes ) ) {
            throw new Exception( sprintf( _n( '%s is a required field', '%s are required fields', count( $missing_attributes ), 'woocommerce' ), wc_format_list_of_items( $missing_attributes ) ) );
          }
        $passed_validation = apply_filters( 'woocommerce_add_to_cart_validation', true, $product_id, $quantity, $variation_id, $variations );
        if ( $passed_validation && false !== WC()->cart->add_to_cart( $product_id, $quantity, $variation_id, $variations ) ) {
          wc_add_to_cart_message( array( $product_id => $quantity ), true );
        }
      }
  }
}
add_action( 'wp_loaded', 'woocommerce_maybe_add_multiple_products_to_cart', 15 );
PHP Snippet 4:
add_action( 'wp_loaded', 'add_multiple_to_cart_action', 20 );
function add_multiple_to_cart_action() {
    if ( ! isset( $_REQUEST['multiple-item-to-cart'] ) || false === strpos( wp_unslash( $_REQUEST['multiple-item-to-cart'] ), '|' ) ) { // phpcs:ignore WordPress.Security.NonceVerification.NoNonceVerification, WordPress.Security.ValidatedSanitizedInput.InputNotSanitized
            return;
        }
    wc_nocache_headers();
    $product_ids        = apply_filters( 'woocommerce_add_to_cart_product_id', wp_unslash( $_REQUEST['multiple-item-to-cart'] ) ); // phpcs:ignore WordPress.Security.NonceVerification.NoNonceVerification
    $product_ids = explode( '|', $product_ids );
    if( ! is_array( $product_ids ) ) return;
    $product_ids = array_map( 'absint', $product_ids );
    $was_added_to_cart = false;
    $last_product_id = end($product_ids);
    //stop re-direction
    add_filter( 'woocommerce_add_to_cart_redirect', '__return_false' );
    foreach ($product_ids as $index => $product_id ) {
        $product_id = absint(  $product_id  );
        if( empty( $product_id ) ) continue;
        $_REQUEST['add-to-cart'] = $product_id;
        if( $product_id === $last_product_id ) {
            add_filter( 'option_woocommerce_cart_redirect_after_add', function() { 
                return 'yes'; 
            } );
        } else {
            add_filter( 'option_woocommerce_cart_redirect_after_add', function() { 
                return 'no'; 
            } );
        }
        WC_Form_Handler::add_to_cart_action();
    }
}
PHP Snippet 5:
function woocommerce_maybe_add_multiple_products_to_cart() {
// Make sure WC is installed, and add-to-cart qauery arg exists, and contains at least one comma.
if ( ! class_exists( 'WC_Form_Handler' ) || empty( $_REQUEST['add-to-cart'] ) || false === strpos( $_REQUEST['add-to-cart'], ',' ) ) {
    return;
}
// Remove WooCommerce's hook, as it's useless (doesn't handle multiple products).
remove_action( 'wp_loaded', array( 'WC_Form_Handler', 'add_to_cart_action' ), 20 );
$product_ids = explode( ',', $_REQUEST['add-to-cart'] );
$quantities = explode( ',', $_REQUEST['quantities'] );
$count       = count( $product_ids );
$number      = 0;
foreach ( $product_ids as $product_id ) {
    if ( ++$number === $count ) {
        // Ok, final item, let's send it back to woocommerce's add_to_cart_action method for handling.
        $_REQUEST['add-to-cart'] = $product_id;
        return WC_Form_Handler::add_to_cart_action();
    }
    $product_id        = apply_filters( 'woocommerce_add_to_cart_product_id', absint( $product_id ) );
    $was_added_to_cart = false;
    $adding_to_cart    = wc_get_product( $product_id );
    if ( ! $adding_to_cart ) {
        continue;
    }
    $add_to_cart_handler = apply_filters( 'woocommerce_add_to_cart_handler', $adding_to_cart->product_type, $adding_to_cart );
    /*
     * Sorry.. if you want non-simple products, you're on your own.
     *
     * Related: WooCommerce has set the following methods as private:
     * WC_Form_Handler::add_to_cart_handler_variable(),
     * WC_Form_Handler::add_to_cart_handler_grouped(),
     * WC_Form_Handler::add_to_cart_handler_simple()
     *
     * Why you gotta be like that WooCommerce?
     */
    if ( 'simple' !== $add_to_cart_handler ) {
        continue;
    }
//         $_REQUEST['quantity'] = ! empty( $id_and_quantity[1] ) ? absint( $id_and_quantity[1] ) : 1;
$_REQUEST['quantity'] = ! empty( $quantities[$number] ) ? absint( $quantities[$number] ) : 1;
    $quantity          = empty( $quantities[$number - 1] ) ? 1 : wc_stock_amount(  $quantities[$number - 1] );
//     $quantity          = empty( $_REQUEST['quantity'] ) ? 1 : wc_stock_amount( $_REQUEST['quantity'] );
    $passed_validation = apply_filters( 'woocommerce_add_to_cart_validation', true, $product_id, $quantity );
    if ( $passed_validation && false !== WC()->cart->add_to_cart( $product_id, $quantity ) ) {
        wc_add_to_cart_message( array( $product_id => $quantity ), true );
    }
}
}
 // Fire before the WC_Form_Handler::add_to_cart_action callback.
 add_action( 'wp_loaded',        'woocommerce_maybe_add_multiple_products_to_cart', 15 );
// remove "added to cart" notice
add_filter( 'wc_add_to_cart_message_html', '__return_false' );
PHP Snippet 6:
add-to-cart=product1id:quantity,product2id:quantity  
PHP Snippet 7:
add_action( 'template_redirect', function() {
    
    if( ! isset( $_POST['products'] ) ) {
        return;
    }
    
    $products = array_filter( $_POST['products'] );
    
    foreach( $products as $product_id => $quantity ) {
        WC()->cart->add_to_cart( $product_id, $quantity );
    }
    
} );
PHP Snippet 8:
https://url.com/shop/cart/?add-to-cart=3001&quantity[2002]=1&quantity[1001]=1
PHP Snippet 9:
class add_more_to_cart {
    private $prevent_redirect = false; //used to prevent WC from redirecting if we have more to process
    function __construct() {
        if ( ! isset( $_REQUEST[ 'add-more-to-cart' ] ) ) return; //don't load if we don't have to
        $this->prevent_redirect = 'no'; //prevent WC from redirecting so we can process additional items
        add_action( 'wp_loaded', [ $this, 'add_more_to_cart' ], 21 ); //fire after WC does, so we just process extra ones
        add_action( 'pre_option_woocommerce_cart_redirect_after_add', [ $this, 'intercept_option' ], 9000 ); //intercept the WC option to force no redirect
    }
    function intercept_option() {
        return $this->prevent_redirect;
    }
    function add_more_to_cart() {
        $product_ids = explode( ',', $_REQUEST['add-more-to-cart'] );
        $count       = count( $product_ids );
        $number      = 0;
        foreach ( $product_ids as $product_id ) {
            if ( ++$number === $count ) $this->prevent_redirect = false; //this is the last one, so let WC redirect if it wants to.
            $_REQUEST['add-to-cart'] = $product_id; //set the next product id
            WC_Form_Handler::add_to_cart_action(); //let WC run its own code
        }
    }
}
new add_more_to_cart;
PHP Snippet 10:
// Make sure WC is installed, and add-to-cart qauery arg exists, and contains at least one comma.
if ( ! class_exists( 'WC_Form_Handler' ) || empty( $_REQUEST['add-to-cart'] ) || false === strpos( $_REQUEST['add-to-cart'], ',' ) ) {
    return;
}
remove_action( 'wp_loaded', array( 'WC_Form_Handler', 'add_to_cart_action' ), 20 );
$product_ids = explode( ',', $_REQUEST['add-to-cart'] );
$quantities = explode( ',', $_REQUEST['quantities'] );
$count       = count( $product_ids );
$number      = 0;
foreach ( $product_ids as $product_id ) {
    if ( ++$number === $count ) {
        // Ok, final item, let's send it back to woocommerce's add_to_cart_action method for handling.
        $_REQUEST['add-to-cart'] = $product_id;
        return WC_Form_Handler::add_to_cart_action();
    }
    $product_id        = apply_filters( 'woocommerce_add_to_cart_product_id', absint( $product_id ) );
    $was_added_to_cart = false;
    $adding_to_cart    = wc_get_product( $product_id );
    if ( ! $adding_to_cart ) {
        continue;
    }
    if ( $adding_to_cart->is_type( 'simple' ) ) {
        $_REQUEST['quantity'] = ! empty( $quantities[$number] ) ? absint( $quantities[$number] ) : 1;
        $quantity          = empty( $quantities[$number - 1] ) ? 1 : wc_stock_amount(  $quantities[$number - 1] );
        // quantity applies to all products atm
        //$quantity          = empty( $_REQUEST['quantity'] ) ? 1 : wc_stock_amount( $_REQUEST['quantity'] );
        $passed_validation = apply_filters( 'woocommerce_add_to_cart_validation', true, $product_id, $quantity );
        if ( $passed_validation && false !== WC()->cart->add_to_cart( $product_id, $quantity ) ) {
            wc_add_to_cart_message( array( $product_id => $quantity ), true );
        }
    } else {
        $variation_id       = empty( $_REQUEST['variation_id'] ) ? '' : absint( wp_unslash( $_REQUEST['variation_id'] ) );
        $quantity           = empty( $quantities[$number - 1] ) ? 1 : wc_stock_amount( wp_unslash( $quantities[$number - 1] ) ); // WPCS: sanitization ok.
        $missing_attributes = array();
        $variations         = array();
        $adding_to_cart     = wc_get_product( $product_id );
        if ( ! $adding_to_cart ) {
          continue;
        }
        // If the $product_id was in fact a variation ID, update the variables.
        if ( $adding_to_cart->is_type( 'variation' ) ) {
          $variation_id   = $product_id;
          $product_id     = $adding_to_cart->get_parent_id();
          $adding_to_cart = wc_get_product( $product_id );
          if ( ! $adding_to_cart ) {
            continue;
          }
        }
        // Gather posted attributes.
        $posted_attributes = array();
        foreach ( $adding_to_cart->get_attributes() as $attribute ) {
          if ( ! $attribute['is_variation'] ) {
            continue;
          }
          $attribute_key = 'attribute_' . sanitize_title( $attribute['name'] );
          if ( isset( $_REQUEST[ $attribute_key ] ) ) {
            if ( $attribute['is_taxonomy'] ) {
              // Don't use wc_clean as it destroys sanitized characters.
              $value = sanitize_title( wp_unslash( $_REQUEST[ $attribute_key ] ) );
            } else {
              $value = html_entity_decode( wc_clean( wp_unslash( $_REQUEST[ $attribute_key ] ) ), ENT_QUOTES, get_bloginfo( 'charset' ) ); // WPCS: sanitization ok.
            }
            $posted_attributes[ $attribute_key ] = $value;
          }
        }
        // If no variation ID is set, attempt to get a variation ID from posted attributes.
        if ( empty( $variation_id ) ) {
          $data_store   = WC_Data_Store::load( 'product' );
          $variation_id = $data_store->find_matching_product_variation( $adding_to_cart, $posted_attributes );
        }
        // Do we have a variation ID?
        if ( empty( $variation_id ) ) {
          throw new Exception( __( 'Please choose product options…', 'woocommerce' ) );
        }
        // Check the data we have is valid.
        $variation_data = wc_get_product_variation_attributes( $variation_id );
        foreach ( $adding_to_cart->get_attributes() as $attribute ) {
          if ( ! $attribute['is_variation'] ) {
            continue;
          }
          // Get valid value from variation data.
          $attribute_key = 'attribute_' . sanitize_title( $attribute['name'] );
          $valid_value   = isset( $variation_data[ $attribute_key ] ) ? $variation_data[ $attribute_key ]: '';
          /**
           * If the attribute value was posted, check if it's valid.
           *
           * If no attribute was posted, only error if the variation has an 'any' attribute which requires a value.
           */
          if ( isset( $posted_attributes[ $attribute_key ] ) ) {
            $value = $posted_attributes[ $attribute_key ];
            // Allow if valid or show error.
            if ( $valid_value === $value ) {
              $variations[ $attribute_key ] = $value;
            } elseif ( '' === $valid_value && in_array( $value, $attribute->get_slugs() ) ) {
              // If valid values are empty, this is an 'any' variation so get all possible values.
              $variations[ $attribute_key ] = $value;
            } else {
              throw new Exception( sprintf( __( 'Invalid value posted for %s', 'woocommerce' ), wc_attribute_label( $attribute['name'] ) ) );
            }
          } elseif ( '' === $valid_value ) {
            $missing_attributes[] = wc_attribute_label( $attribute['name'] );
          }
        }
        if ( ! empty( $missing_attributes ) ) {
          throw new Exception( sprintf( _n( '%s is a required field', '%s are required fields', count( $missing_attributes ), 'woocommerce' ), wc_format_list_of_items( $missing_attributes ) ) );
        }
      $passed_validation = apply_filters( 'woocommerce_add_to_cart_validation', true, $product_id, $quantity, $variation_id, $variations );
      if ( $passed_validation && false !== WC()->cart->add_to_cart( $product_id, $quantity, $variation_id, $variations ) ) {
        wc_add_to_cart_message( array( $product_id => $quantity ), true );
      }
    }
}
PHP Snippet 11:
/*
 * Init function
 * 1. Apply coupon code from URL
 * 2. Add to cart: Multiple products add via URL
 */
function nd_template_redirect() {
    if( !isset( WC()->session ) || ( isset( WC()->session ) && !WC()->session->has_session() ) ) {
        WC()->session->set_customer_session_cookie( true );
    }
    
    $product_ids = array();
    $quantities  = array();
    
    if( isset( $_GET['add-to-cart'] ) ) {
        if( false !== strpos( $_GET['add-to-cart'], ',' ) ) {
            $product_ids = explode( ',', $_GET['add-to-cart'] );
        }
    }
    
    if( isset( $_GET['quantity'] ) ) {
        if( false !== strpos( $_GET['quantity'], ',' ) ) {
            $quantities = explode( ',', $_GET['quantity'] );
        }
    }
    
    if( !empty( $product_ids ) ) {
        $products = array();
        
        for( $i = 0; $i < count( $product_ids ); $i++ ) {
            if( isset( $product_ids[ $i ] ) ) {
                $products[ $product_ids[ $i ] ] = isset( $quantities[ $i ] ) ? $quantities[ $i ] : 1;
            }
        }
        
        if( !empty( $products ) ) {
            foreach( $products as $key => $value ) {
                WC()->cart->add_to_cart( $key, $value );
            }
        }
    }
    
    if( isset( $_GET['coupon_code'] ) && empty( WC()->session->get( 'added_coupon_code' ) ) ) {
        $coupon_code = esc_attr( $_GET['coupon_code'] );
        
        if( !empty( $coupon_code ) && !WC()->cart->has_discount( $coupon_code ) ) {
            WC()->cart->add_discount( $coupon_code );
            
            WC()->session->set( 'added_coupon_code', true );
        }
    }
}
add_action( 'template_redirect', 'nd_template_redirect' );
/*
 * Clear session variables on thank you page.
 */
function nd_woocommerce_thankyou( $order_id ) {
    WC()->session->__unset( 'added_coupon_code' );
    WC()->session->__unset( 'added_products_to_cart' );
}
add_action( 'woocommerce_thankyou', 'nd_woocommerce_thankyou' );