Add quantity to the archive page

gistfile1.txt

add_action( 'woocommerce_after_shop_loop_item', 'my_custom_quantity_field', 9 ); 
function my_custom_quantity_field() {
  global $product;
  if ( ! $product->is_sold_individually() )
    woocommerce_quantity_input( array(
      'min_value' => apply_filters( 'woocommerce_quantity_input_min', 1, $product ),
      'max_value' => apply_filters( 'woocommerce_quantity_input_max', $product->backorders_allowed() ? '' : $product->get_stock_quantity(), $product )
    ) );
}