In magento 2 I had created 3 product via my code. Product type is configurable, simple, simple. so now don't know set two simple product into configuration product. thank for help!
You can associate the simple products by loading the Configurable product.
Inject the below Class to Construct Method \Magento\Catalog\Model\ProductRepository $productRepository,
So, $this->_productRepository = $productRepository;
Assuming the id of the configurable product as '3' and the simple as ,'1' and '2' respectively.
$associatedProductIds = [2,3];//Simple Product ids array
$configurableProduct = $this->_productRepository->getById(3);
Hope this helps