i want to check the size of row 5..and how many integers it contains...how do i ask for that?.. 
holder[4].size();
holder.size()..is surely not enough right??? that will give me the size of the whole 2d i think 
holder
is a vector. Each element of the vector is a row. (A "row" is, in fact, another vector, but that's not important right now.) So holder.size()
will give you the number of elements in holder
 i.e. the number of rows.




holder
is a single vector of rows.
holder
is really the entire 2dimensional "table". It contains all the rows, which in turn contain all the integers.holder[i]
is a single "row". It contains all the integers in that row.holder[i][j]
is a single element  that is, a single integer.







