Compare two text files line by line [closed]

Answer 1

Since your question seems like you made no effort whatsoever I'll give you just a rough outline.

1. Read both files line by line, e.g. with File.ReadAllLines or File.ReadLines.
2. Use LINQ's Except method.
3. Write the results into a new file.

Answer 2

String directory = @"C:\Whatever\";
String[] linesA = File.ReadAllLines(Path.Combine(directory, "FileA-Database.txt"));
String[] linesB = File.ReadAllLines(Path.Combine(directory, "FileB-Database.txt"));

IEnumerable<String> onlyB = linesB.Except(linesA);

File.WriteAllLines(Path.Combine(directory, "Result.txt"), onlyB);