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

So you want the last index before a given index...

var myString = "this is a test string that contains other string for testing";
myString = String.SubString(0, 53);
var lastIndexOf = myString.LastIndexOf("string");