You're using print() wrong!
It's likely that the first line of Swift you wrote went something like this: print("Hello, world!") I'm telling you today that you're doing it wrong . What's wrong with print statements!? When you print in Swift, you send a text stream to an output device (i.e. the console screen). This is extremely useful for debugging, but when used in production there are 2 major problems: 1. Security 2. Inefficiency 1. What are the security issues with print()? When printing to the console, the output is accessible to your app's users - if a bad actor knows what she is doing, she can connect her device to a computer and read the live print statements of running apps. As a side note - the exact same is true with your app's network calls by using Charles Proxy , so make sure not to send any sensitive data to the client! It's very easy to leave print statements for debugging forgotten about printed out in a live...