Analysis skeleton for a TChain

Hi again guys,
sorry for my naive questions. I’m still trying to understand the logic of ROOT.
Following my previous topic How to read array variable in a Tree , I create the .h and .C (and modify it) files but I cannot understand how to generalize this to more root file. I followed the indication provided me by one answer of @Wile_E_Coyote and I understood that I need to use TChain and I read on the Manual on how to use it. I understood it how to use but not the connection with the previous point. I mean, do I have to create a new file with the TChain where I define the variable and assigm to a branch (as: chain.SetBranchAddress(…,&)) or do I have to use the previous .h .C files (created by a single root file, but with the same structure of the other root file)? or Do I have to add the Chain inside the .h file created before. I’m a bit confused…
Sorry for the naive question but it’s not clear to me how to implement this thing.
Thanks much.

ROOT Version: 5.37/38
Platform: Unix CentOS 7.9.2009
Compiler: CINT 5.18

Generate an “analysis skeleton” for the whole TChain, e.g.:

  TChain *t = new TChain("Data");
  delete t;

Yes, I followed this link that you sent me, but couldn’t understand this point.
Ah ok, so it is independent from the single TTree class! It’s what I wanted to know.
I was confused by what was written in the tree.h file where it says:

TTree          *fChain;   //!pointer to the analyzed TTree or TChain

so I didn’t get if to put there the chain or not.
Thanks for clarified it.