First index before a position

Question

I have a string and index in that string, and want to get the first position of a substring before that index.

e.g., in string:

\"this is a test string tha

Answer 1

I know I am late to the party but this is the solution that I am using:

    public static int FindIndexBefore(this string text, int startIndex, string searchString)
    {
        for (int index = startIndex; index >= 0; index--)
        {
            if (text.Substring(index, searchString.Length) == searchString)
            {
                return index;
            }
        }

        return -1;
    }

I tested it on your example and it gave the expected results.