Change product price in WooCommerce programmatically

/**
 * Sets product price.
 *
 * @see https://wpcodebook.com/change-product-price-in-woocommerce-programmatically/
 *
 * @param int|WC_Product $product Product ID or WC_Product object.
 * @param string $price Price.
 * @param string $regular_or_sale Price type. Possible values: regular, sale. Default: regular.
 * @param bool $apply_to_all_variations Whether to set the price for all product variations as well. Default: false.
 *
 * @return bool
 */
function wpcodebook_set_product_price( $product, $price, $regular_or_sale = 'regular', $apply_to_all_variations = false ) {

	if ( is_numeric( $product ) ) {
		$product = wc_get_product( $product );
	}

	if ( ! $product ) {
		return false;
	}

	if ( ! $product->is_type( 'variable' ) ) {

		if ( 'sale' === $regular_or_sale ) {
			$product->set_sale_price( $price );
		} else {
			$product->set_regular_price( $price );
		}

		$product->save();

	} else {

		if ( ! $apply_to_all_variations ) {
			return true;
		}

		foreach ( $product->get_children() as $variation_id ) {
			if ( ! wpcodebook_set_product_price( $variation_id, $price, $regular_or_sale ) ) {
				return false;
			}
		}

	}

	return true;

}