as part of the eway API here: https://eway.io/api-v3/?php#errors
they have this code (in PHP).
$apiKey = '60CF3Ce97nRS1Z1Wp5m9kMmzHHEh8Rkuj31QCtVxjPWGYA9FymyqsK0Enm1P6mHJf0THbR';
$apiPassword = 'API-P4ss';
$apiEndpoint = \Eway\Rapid\Client::MODE_SANDBOX; // Use \Eway\Rapid\Client::MODE_PRODUCTION when you go live
$client = \Eway\Rapid::createClient($apiKey, $apiPassword, $apiEndpoint);
what is the backslash characters all about? I've never seen them in PHP like this before. It seems to be a way to interact with classes. But I can't find anywhere to learn about this way of doing so. Can someone explain what it's about or point to resources that can? (Ideally not just technical jargon websites please).
Why not use a more known way of class interaction in their API documentation?