adding data to a text file after textfile validation C# code example

Example: c sharp how to read a text file

// To save the text as one string use 'ReadAllText()'
string text = System.IO.File.ReadAllText(@"C:\filepath\file.txt");
// To save each line seperately in an array use 'ReadAllLines()'
string[] lines = System.IO.File.ReadAllLines(@"C:\filepath\file.txt");