Can't get multiple PHP versions on Ubuntu server 16.04?

Question

PHP

Others, it’s impossible to get 7.1 or 7.3 on a working server (what is stable there?)
littered the entire OS, and 5.6 costs (which really works) and 7, 7.0 - 7.3
xs which works, which just takes up space ..
completely broke my head .. .. :((((
Task: to make it so that with the currently working 5.6 everything smoothly switched to 7. *
in the internet there is a bunch of information that sometimes contradicts itself ...

Answer 1

I would make an intermediate version of 7.2, because. 7.3 breaks some things with the switch.
I don’t see any problems if you have development skills in PHP. You raise different versions side by side and then reload nginx.