How to get order collection in magento2 ?

With below piece of code we can easily get a order collection in magento2  easily by using object manager


> to get order collection 
 
<?php $objectManager =  \Magento\Framework\App\ObjectManager::getInstance();
     $orderDatamodel = $objectManager->get('Magento\Sales\Model\Order')->getCollection();
     foreach($orderDatamodel as $orderDatamodel1){
     print_r($orderDatamodel1->getData());
   
     }



- > to get order collection with order items data

     <?php $objectManager =  \Magento\Framework\App\ObjectManager::getInstance();
     $orderDatamodel = $objectManager->get('Magento\Sales\Model\Order')->getCollection();
     foreach($orderDatamodel as $orderDatamodel1){
     $getid =  $orderDatamodel1->getData("increment_id");
         $orderData = $objectManager->create('Magento\Sales\Model\Order')->loadByIncrementId($getid);
          //echo "<pre>";
          $getorderdata = $orderData->getData();
          $orderItems = $orderData->getAllVisibleItems();
          foreach($orderItems as $orderItems){
                    print_r($orderItems->getData());
        }
     }