Code-Snippets-Functions/Execute a function on a child site/WooCommerce/set-default-shipping-class-for-all-products.txt

add_filter( 'woocommerce_product_get_shipping_class_id', 'wc_default_product_shipping_class', 9999, 2 );
  
function wc_default_product_shipping_class( $value, $product ) {
   $value = $value ? $value : 44; // default to shipping class ID = 44
   return $value;
}