string.LastIndexOf()

Question

Hi guys. I don't know if it is only me,or what,but simple function from class String - LastIndexOf() works for me well only if there is only first attribute assigned and nothing else. If I try write something like this : string strS = "abcdefghijkl"; int a = strS.LastIndexOf("c",0,5); it always throw exception : Count must be positive and count must refer to a location within the string/array/collection. Does it happend to You too or is just something wrong with me ? Thanks. Rodenpro

info · Answer

Thank you very much. Hmm..realy not intuitive at all !!. Thanks.Appreciate. Rodenpro.

ytram5 · Answer

Ok, figured it out. The LastIndexOf method will scan backward , not forwards, so it is essentially asking for a backwards substring. Using your example: strS = "abcdefghijkl"; int a = strS.LastIndexOf("c",0,5) //will throw an exception int b = strS.LastIndexOf("c",6,5) //This will examine the substring "cdefg" for the string "c". It's not as intuitive as IndexOf's overload similar to this. Here is the URL where I got this information: http://msdn.microsoft.com/library/default.asp?url=/library/en-us/cpref/html/frlrfsystemstringclasslastindexoftopic6.asp

ytram5 · Answer

I am testing this, and getting the same exception. It's extremely odd, as count shouldn't refer to a location, it is the number of characters to scan.

string.LastIndexOf()

Answers (3)