Question

I have the following text in a string that always ends in a “?”.

"Which of the following can be abc def ghi?"
"Which of the following can be hello?"

Can someone tell me how I can check to see if this text contains:

"Which of the following <any string of text here>?"

and if it contains that then how can I get the text “abc def ghi” and “hello”

Answer 1

const string constantValue = "Which of the following can be ";
var theString = "Which of the following can be abc def ghi?";
var index = theString.IndexOf(constantValue);

string result = "";
if (index > -1)
    result = theString.Substring(constantValue.Length, 
                            theString.Length - constantValue.Length - index - 1);

Edit:
This regex should match all the inputs from your other question:

var text = "1 - Which of the following is a aa mmm zz?\n" +
"2 - Which of the following is true?\n" +
"3 - Which of the following can be aa mmm zz?\n" +
"4 - Which of the following are correct?\n" +
"5 - What will be the result when aa mmm zz?\n" +
"6 - What will result when aa mmm zz?\n" +
"7 - Which are aa mmm zz?\n" +
"8 - What can be said about aa mmm zz?\n";

var regex = @"What (can be said about |will (be the )?result when )(?<result>.*?)\?|Which (of the following )?(can be|are|is|is a) (?<result>.*?)[?:]";
var matches = Regex.Matches(text, regex);

foreach (Match match in matches)
{
    Console.WriteLine("result: " + match.Groups["result"]);
}