using System.Text.RegularExpressions;
public static void Main()
string[] strs = new string[] {"\\", "\"", "\n", "", null};
Console.WriteLine("Hello World");
foreach (string str in strs)
Console.WriteLine(JsonConvert.SerializeObject(str));
Console.WriteLine( String.Format("\"{0}\"", Regex.Escape(str)));
Console.WriteLine("==================");