Open text file, loop through contents and check against

Question

So I have a generic number check that I am trying to implement:

    public static bool isNumberValid(string Number)
    {
    }

And I want to

Answer 1

You need to replace your loop to look like this:

string[] lines = File.ReadAllLines(file);
foreach (var s in lines)
{
  int number = int.Parse(s);
  ...
}

This would read each line of file, assuming that there is only one number per line, and lines are separated with CRLF symbols. And parse each number to integer, assuming that integer is not greater than 2,147,483,647 and not less than -2,147,483,648, and integers are stored in your locale settings, with or without group separators.

In case if any line is empty, or contains non-integer - code will throw an exception.