Hello,

I am asking you, for example when I edit functions.php and when a new major release will come, will I lose my changes when doing the update? If the answer is yes, how can I keep my edits on major releases updates?

Thank you,

Yes it will, for that reason in next version there will be support for custom functions file in theme folder.

Hello,

I am asking you, for example when I edit functions.php and when a new major release will come, will I lose my changes when doing the update? If the answer is yes, how can I keep my edits on major releases updates?

Thank you,

Make a "fake" plugin with only all those custom functions. Simple as that. Takes 5 minutes. Solves the issue forever.

Thats solution as well 

Had this issue in the past, so this is not an option, as lines and code always changes.

Does child-theme works for my situation?

Which one please? It's not clear.

When upgraded from 8.0 to 8.0.1 to 8.0.2 all my changes that I did in the .php files has been lost.

All of them were saved on an external doc, but when I tried to put them back, found that not all the lines were the same. Your releases came with changed lines and code. So, I was not able to keep all the modifies I did peviously, as I didn’t knew how and where to put the code again, as I had errors, so some of the changes have been lost.

So how can I avoid this? Using the child-theme? I don’t think… as the update goes for it too.

Is there any way to keep my changed code on major release?

Of course, upgrade rewrite all files it contains, that is essential.
Child theme is not in .zip so it will not be affected, it's not updated.

Of course, upgrade rewrite all files it contains, that is essential.
Child theme is not in .zip so it will not be affected, it's not updated.

So my question, is there any way to keep all my modifies on major updates?
As lines and code are also changed from release to release and I did not managed to find their place back as it was before.

Thank you,

Answer is: use child theme.