$product_id = 1234; $attribute_id = 5678; $new_value = 'red'; // Update the default attribute value for the product $update = Mage::getModel('catalog/product_action')->updateDefaultAttribute($product_id, $attribute_id, $new_value);In this example, we are updating the default attribute value for a product with an ID of 1234. The attribute we want to update has an ID of 5678, and we want to set the default value to 'red'. This function is part of the Magento package library, which is a popular e-commerce platform for online stores.