Easiest way to split a string on newlines in .NET?

Question

I need to split a string into newlines in .NET and the only way I know of to split strings is with the Split method. However that will not allow me to (easily) split on a ne

Answer 1

Very easy, actually.

VB.NET:

Private Function SplitOnNewLine(input as String) As String
    Return input.Split(Environment.NewLine)
End Function

C#:

string splitOnNewLine(string input)
{
    return input.split(environment.newline);
}

Answer 2

Examples here are great and helped me with a current "challenge" to split RSA-keys to be presented in a more readable way. Based on Steve Coopers solution:

    string Splitstring(string txt, int n = 120, string AddBefore = "", string AddAfterExtra = "")
    {
        //Spit each string into a n-line length list of strings
        var Lines = Enumerable.Range(0, txt.Length / n).Select(i => txt.Substring(i * n, n)).ToList();
        
        //Check if there are any characters left after split, if so add the rest
        if(txt.Length > ((txt.Length / n)*n) )
            Lines.Add(txt.Substring((txt.Length/n)*n));

        //Create return text, with extras
        string txtReturn = "";
        foreach (string Line in Lines)
            txtReturn += AddBefore + Line + AddAfterExtra +  Environment.NewLine;
        return txtReturn;
    }

Presenting a RSA-key with 33 chars width and quotes are then simply

Console.WriteLine(Splitstring(RSAPubKey, 33, "\"", "\""));

Output:

Hopefully someone find it usefull...

Answer 3

For a string variable s:

s.Split(new string[]{Environment.NewLine},StringSplitOptions.None)

This uses your environment's definition of line endings. On Windows, line endings are CR-LF (carriage return, line feed) or in C#'s escape characters \r\n.

This is a reliable solution, because if you recombine the lines with String.Join, this equals your original string:

var lines = s.Split(new string[]{Environment.NewLine},StringSplitOptions.None);
var reconstituted = String.Join(Environment.NewLine,lines);
Debug.Assert(s==reconstituted);

---

What not to do:

• Use StringSplitOptions.RemoveEmptyEntries, because this will break markup such as Markdown where empty lines have syntactic purpose.
• Split on separator new char[]{Environment.NewLine}, because on Windows this will create one empty string element for each new line.

Answer 4

Silly answer: write to a temporary file so you can use the venerable File.ReadLines

var s = "Hello\r\nWorld";
var path = Path.GetTempFileName();
using (var writer = new StreamWriter(path))
{
    writer.Write(s);
}
var lines = File.ReadLines(path);