how to split a string with strings in c#
string[] separatingStrings = { "<<", "..." };
string text = "one<<two......three<four";
System.Console.WriteLine($"Original text: '{text}'");
string[] words = text.Split(separatingStrings, System.StringSplitOptions.RemoveEmptyEntries);
System.Console.WriteLine($"{words.Length} substrings in text:");
foreach (var word in words)
{
System.Console.WriteLine(word);
}