There are two ways to split string in C# ASP.Net, you can use Regex to split the string if you want to split between words. But if you want to split only one single character, you can use the Split function from String object.

See below example for more details:

//first example split a single character
string sampleString = "1,2,3,4,5";
string[] arrayString = sampleString.Split(',');
foreach (string str in arrayString) {
	Response.Write(str + ", ");
}

//second example split a word
string sampleSentence = "Run and faster and go and higher";
string[] arrayWord = System.Text.RegularExpressions.Regex.Split(sampleSentence, "and");
foreach (string str in arrayWord) {
	Response.Write(str + ", ");
}