iOS Force Quit - data/app damage?

Thank you much.

The Apple instructor for our Apple Business Joint Venture (Mac & iDevice) training class indicated it'd very likely damage data and/or cause problems resulting with the apps running improperly. He said he *never* closes any app. This seemed unlikely for the reason you mentioned - programs have the be more durable (stable) in case of interruptions of any kind, espec power interruptions or internet connections.

Force Quitting for the OCD of us (my wife & I at least) seems like just another tidy thing to do like closing Apps on Macs. I can't not - old habit I guess.

Update:

After my earlier post, we loaded an app from the icon (eBay) which was "open" in the tray and upon opening, it showed the previous activity as something that looked like what we used to call machine language in early PC days. It was unreadable letters & symbols.

I Force Quit the App & reloaded it. It was then fine.

POINT: The only way to fix the App problem was to Swipe Up & Force Quit. It was the only time I've seen that kind of distortion in an App and it was apparently because it hadn't been freshly loaded.

Appears that it's sometimes better when an App is loaded anew not the reverse, as was told us by the Apple instructor.

(And the private training costs are part of our annual Jt Venture membership, so it wasnt just a random free class.)