TstringList In Delphi

To add data, you'll do something like:

SLst := TStringList.Create;
//To add string to a TStringList:
SLst.Add('This is a string');
//or
SLst.Add(VariableName);

//To add integer
SLst.Add(IntToStr(55));
//or
SLst.Add(IntToStr(VariableName));

you'll define SLst by:

var
  SLst: TStringList;

And if you want to load it from a textfile:

SLst.LoadFromFile('C:\myfile.txt');

And what do you mean by count the same data? You mean to count how much lines there are in the File? If yes, then:

Count := SLst.Count;

But if you want to show the data in a Memo, then do the following instead of all the above code:

Memo1.Lines.LoadFromFile('C:\myfile.txt');
Count := Memo1.Lines.Count;

I hope my answer helped.