Duplicating files

[bpedit]

It seems there should be a way to store incremental (version) files during the development of a project within the same project. For example, being able to copy and then modify a new main.m file while preserving the old one (understanding the old main would have to be somehow disabled). The idea being:
  •  keeping the older files for academic purposes.
  •  having back-ups to return to for modification.
  •  having all versions contained within one project.

So far I've figured two ways to duplicate:
  •  copy the entire folder that Xcode creates.
  •  create a new project and drag files from the old project.
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edit: Oops! Even these don't work. The modification in the new file are also applied to the old file; they remain the same file. The only way I've found is to create a new project with new files then cut-and-paste from the old project files.
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[Waiting]

Have a look at the GIT repository option when you start a new project.

This can help you save versions and go back and compare next to each other the difference.

It might not be exactly what you want but could be useful. Maybe have a search on it and read up on if it does what you want.

[bpedit]

Thanks. After a brief look, the GIT method seems like it has its own learning curve and might be overkill for working through examples in the book. I guess I'll cut-and-past for now.
Byrne