Nothing, great to see, Did not mean to offend
Only Cerion used
[I work in an office with 100% male, would prefer 100% female. (maybe)]
If you declare an array
ie int MyArray
it has elements from 0 to 99
if you index it 1 to 100 you will cause problems as the element indexed as 100 is outside the arrays memory.
In debug mode this will not be obvious as you will probably only be over-writting debug info from the compiler. In release mode this will probably crash the program or worse.
(an eye for detail stops many crashes before they happen)