What goes wrong with combining multicolumn and tabular

Question

When I try the following code I get some errors about misplaced \noalign, however I almost entirely copied the code from the wikipage. What is going wrong?

\begin{table}[hbt]
\centering
\begin{tabular}{|>{\centering}m{2cm}<{\centering}|>{\centering}m{2cm}<{\centering}|>{\centering}m{2cm}<{\centering}|>{\centering}m{2cm}<{\centering}|>{\centering}m{2cm}<{\centering}|}
\hline
A&I&J&K&L\\\hline
B&\verb/--/&\verb/++/&\verb/++/&\verb/++/\\\hline
C&\verb/++/&\verb/+/&\verb/-/&\verb/--/\\\hline
D&\verb/--/&\verb/-/&\verb/++/&\verb/+/\\\hline
E&\multicolumn{2}{c}{F}&G&H\hline
\end{tabular}
\end{table}

Answer 1

You are short a \\ in the final row before \hline. Here's your code snippet in the form of a minimal document with some modifications using array to set a column type M (rather than duplicating the same column perpetually):

\documentclass{article}
\usepackage{array}% http://ctan.org/pkg/array
\newcolumntype{M}{>{\centering\arraybackslash}m{2cm}<{\centering\arraybackslash}|}
\begin{document}
\begin{table}[hbt]
  \centering
  \begin{tabular}{|*{5}{M}}
    \hline
    A & I & J & K & L \\ \hline
    B & \verb/--/ & \verb/++/ & \verb/++/ & \verb/++/ \\ \hline
    C & \verb/++/ & \verb/+/  & \verb/-/  & \verb/--/ \\ \hline
    D & \verb/--/ & \verb/-/  & \verb/++/ & \verb/+/  \\ \hline
    E & \multicolumn{2}{c}{F} & G & H \\ \hline % <--- missed "\\"
  \end{tabular}
\end{table}
\end{document}​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​