Answer 1

It does not give the same result as y=x. And ++x is not postfix, its prefix. while x++ may make y = x, it will also increment x.

There's already many explanations here on that concept, here's a few:

https://www.sololearn.com/Discuss/305422/?ref=app
https://www.sololearn.com/Discuss/336732/?ref=app
https://www.sololearn.com/Discuss/223343/?ref=app

Try to write a program involving it, and you will understand it quickly.