IndexOutOfRangeException problem with code

nope... Additional information: Index was outside the bounds of the array.

for(index2 = a; index2 < loopLength ; index2++) ?

hi sorry the previous explanation was a bit lacking... so, pitchNumb is initialised earlier as a static int as i use it in another method later on... FileReaderUtil.SplitFileByLine(FileName) just splits a text file into lines and stores them in an array. ive had a little go at improving the code: (the Parse(string FileName)) method is the same as before).... public static void newMethod() { int index = a; // a is init to 0 while (index < fileLines.Length) // fileLines.Length is the total number of lines in the file, which for this file is 13968 { // loopLength is 36 for(index2 = a; index2 <= loopLength ; index2++) { fileLine = fileLines[index2].Trim(); if( fileLine.Length != 0 ) { pitch1 = fileLine.Substring(5, 1).Trim(); if (pitch1 == "O") { pitchTot++; } pitchArray[pitchNumb] = pitchTot; } index++; } pitchNumb++; } printarray(); // should simply print out the number of "O"s found for each //index of the pitchArray. the array has 388 indices (388*36=13968) } so what actually happens now is this: pitch number 1 is: 10 pitch number 2 is: 20 pitch number 3 is: 30 pitch number 4 is: 40 pitch number 5 is: 50 pitch number 6 is: 60 : : pitch number 383 is: 3830 pitch number 384 is: 3840 pitch number 385 is: 3850 pitch number 386 is: 3860 so it finds 10 occurrences of "O" for the first 36 lines (which is correct) and then instead of finding how many occurrences of "O" there are in the next 36 lines, then the next etc, and storing them in their respective array indices, it just increments each indices by 10 unitl the end of the file is reached. so do you know from looking at this how i can assign each indices of the pitchArray to the correct value of "O"s found for the corresponding set of lines in the file? if anyone can see a glaringly obvious mistake, please point it out to me!! thanks for you time!