how to change the name of exporting file automatically

Question

I want to export some sort of data from Mathematica to .txt files but every time with a different name.clearly I want the name of files change automatically in each loop for each series of data that are produced in each iteration.

s = -1 
While[s < 2*q = 2.;
  \[CapitalDelta] = 0.5;
  smin = -0.3;
  smax = 0.1;
  \[CapitalDelta]s = 0.01;
  L = 5;
  p = 2^L;
  s = s + 0.05;
  H = {{1, 0, 0, 0}, {0, 1 - (\[CapitalDelta] + 1)*q, E^s/q, E^s/q}, 
       {0, q E^s, 1 - (\[CapitalDelta] + 1)/q, q E^s}, 
       {0, \[CapitalDelta]*q*E^s, (\[CapitalDelta]*E^s)/q, 1 - (q + 1/q)}};
  IM = IdentityMatrix[2];
  row = ConstantArray[1, p];
  sum = row.H;
  Export["sum,L=5,q=2,d=0.5,s=-1.txt", sum];
  Export["H,L=5,q=2,d=0.5,s=-1.txt", Flatten[H], "Table"]
  ];

I want to change "s" in the name of the files each time with the real value of it in that itteration

Answer 1

Instead of "H,L=5,q=2,d=0.5,s=-1.txt" write for example:

"H,L=5,q=2,d=0.5,s="<>ToString[CForm[s]]<>".txt"

Answer 2

A very simple solution using TextString and StringJoin:

Export[StringJoin["C:\\Users\\...\\first_part_of_name", TextString[variable], ".txt"], sum];

Answer 3

You could generate the filenames using StringTemplate with a positional argument:

s=-1;
mytemplate := StringTemplate["sum, L=5, q=2, d=0.5, s=`svalue`.txt"]
filestring = mytemplate[<|"svalue" -> ToString[s]|>]

(* sum,L=5,q=2,d=0.5,s=-1.txt *)

Answer 4

There is a simple way if you are using the Table[] function. For example: Table[Export[NotebookDirectory[]<>ToString@StringForm["test``.txt", l], Table[{l,l^2}, {l, 1, 10}];. In this case, the program will generate ten files written as "testl.txt" for each l with the values l and l^2 as columns.