ViewController in Xcode

I don't really understand your question, but since you explicitly use the xcode tag, I understand that it is a question about how to use the Xcode itself.

If you run the app from Xcode, the output of print in the app will be output to the debug console in the debug area.When you say "Output Window Open", you can read as if you were expecting something new to open, but only a small debug area (debug area) appears at the bottom of the screen (in standard condition) and is printed to the debug console in the right half.

In rare cases, even the debug area may not appear after you close the debug area yourself, but in that case, try opening the debug area directly by using the button in the upper right corner of the Xcode window.

If you have something else you would like to ask, edit your question to describe the situation in more detail and more accurately (*1).

*1 For example, if a project was created using Single View Application, the filename should be View.controller.swift, not ViewController.swiftAs programming often results completely differently with just one letter difference (including case differences), you should try to be as accurate as possible.