forloop and table in LaTeX - for-loop

Question

Here is the LaTeX code for my table:
\begin{table}{| c || c | c | c || c | c | c | }
\caption{Examples of the concepts. \label{tab:conceptsimgs}}\\
\hline
\backslashbox{Concept}{Class} &\multicolumn{3}{|c||}{Negative Class} & \multicolumn{3}{|c|}{Positive Class} \\
\hline
\forloop{themenumber}{1}{\value{themenumber} < 4}{
%\hline
\arabic{themenumber}
\forloop{classnumber}{0}{\value{classnumber} < 2}{
\forloop{imagenumber}{1}{\value{imagenumber} < 4}{
& 0
}
}
\\
\hline
}
\end{table}
Something is wrong in the result however. There is some extra thing at the end of the table, as shown in here:
http://www. freeimagehosting. net/image.php?c702bfc838.png
How can I fix it?

Answer 1

That's a nasty one. I've created a minimal example that demonstrates the problem, see below. Try to compile this and take a look at the results.
The point is, you seem to be out of luck — tabular does not like the output of forloop, it cannot disregard the last \addtocounter command. Maybe you can find some other package for loops.
You should be able to figure out the rest from the code below, if not, write a comment.
\documentclass{article}
\usepackage{forloop}
\newcounter{themenumber}
\newcounter{test}
\begin{document}
% this is your table (minimal example)
\begin{tabular}{| c |}
\forloop{themenumber}{1}{\value{themenumber} < 2}{x\\ \hline}
\end{tabular}
\vspace{2cm}
% this is what you wanted to have
\begin{tabular}{| c |}
x \\ \hline
\end{tabular}
\vspace{2cm}
% this is what forloop produces
\begin{tabular}{| c |}
x \\ \hline \addtocounter{test}{1}
\end{tabular}
\end{document}