WooCommerce: Set default order on shop page to by price, title or date

woocommerce-change-shop-page-order-by

/**
 * Change the default shop page 'catalogue' order of how products are displayed
 *
 * You can use the following parameters:
 * 'menu_order' – by the custom order first, then by product name (Default)
 * 'popularity' – by the number of sales
 * 'rating'     – by the average rating
 * 'date'       – recently added products will be displayed first
 * 'price'      – cheapest products will be displayed first
 * 'price-desc' – the most expensive first
 * 'rand'       – in a random order
 *
 * @param $sort_by
 * @return string
 */
function zpd_wc_default_shop_page_orderby( $sort_by ): string {

	/**
	 * You can add conditions to this function - example changing the default ordering of a specific category
	 */
	if( is_product_category( 'nicknacks' ) ) {
		return $sort_by; // no changes for nicknacks category
	}

	return 'price-desc';
}
add_filter('woocommerce_default_catalog_orderby', 'zpd_wc_default_shop_page_orderby', 10, 1 );