• Used to read and write in-memory strings.
• StringWriter uses a StringBuilder behind the scenes.

StringWriter a = new StringWriter();
a.Write("Hello World!");
a.Write(a.NewLine);
a.Write("I span two lines!");
 
StringReader r = new StringReader(a.ToString());
 
while (r.Peek() != -1)
{
    Console.WriteLine(r.ReadLine());
}