how to remove particular string from another string in c# without index code example

Example 1: remove all text after string c#

string input = "text?here";
int index = input.LastIndexOf("?"); // Character to remove "?"
if (index > 0)
    input = input.Substring(0, index); // This will remove all text after character ?

Example 2: c# remove character from string at index

string s = "This is string";
s = s.Remove(2, 1);
//Output: Ths is string


string s = "This is string";
s = s.Remove(2, 2);
//Output: Th is string