The output of my program is a table in a file.
Some users like the output as Excel file, the others prefer CSV, and so on.
I therefore have an abstarct class Document with 2 derived classes:
ExcelDocument and CsvDocument.
The delimiter between the output results is different in each class:
In the CSV file the delimiter is , and in the Excel the delimiter is /t.
How can I force the derived classes to set value to the delimiter attribute of the abstract Document class?