Magento2 : Best way to load Customer by customer Id

Question

What is the best way to load Customer by Id? using customer interface or customer factory or another way ?
In most of solutions I found, it is done by directly using objectManager (which should be never be used).

Answer 1

It's always a better practice to use service contracts.

In your case I would use \Magento\Customer\Api\CustomerRepositoryInterface :

protected $_customerRepositoryInterface;
public function __construct(
    ....
    \Magento\Customer\Api\CustomerRepositoryInterface $customerRepositoryInterface,
    ....
) {
    ....
    $this->_customerRepositoryInterface = $customerRepositoryInterface;
}

Then in your code you can call:

$customerId = 1;
$customer = $this->_customerRepositoryInterface->getById($customerId);