Error: extra alignment tab has been changed to \cr

Question

I am using the ACM SIG template and trying to create a table of 4 columns.

I get the error mentioned in the title of the question. I know the standard reasons why this error can occur.

But my question is: Is it possible that the template or .cls file is controlling the maximum number of columns in a table ? If it were, would I get a different error than this?

Answer 1

The error can be reproduced by

\documentclass{article}

\begin{document}

\begin{tabular}{c|c}
one & two & three \\
\hline
one & two 
\end{tabular}
\end{document}

The problem is caused by the extra column you try to insert. The tabular environment expects two columns but three is inserted.

Answer 2

Another way to get a ! Extra alignment tab has been changed to \cr error is to use an alignment command (\centering, \raggedleft, \raggedright) in the last row of a tabular environment (when using p{} formatting, of course).

For example, this code will give an error:

\begin{tabular}{|p{0.2\textwidth}|p{0.2\textwidth}|}
     A & \centering B \\
    C & D \\    
\end{tabular}

But this code will not:

\begin{tabular}{|p{0.2\textwidth}|p{0.2\textwidth}|}
     \centering A &  B \\
     \centering C & D \\    
\end{tabular}

We can use the environment center to overcome this problem, with the caveat that we will have extra vertical spaces. (needless to say, you may change to c column formatting, if you are willing to give up width control ;))

A quick fix for the problem is to add a zero-width column, e.g., p{0pt}

Quick fix solution:

\begin{tabular}{|p{0.2\textwidth}|p{0.2\textwidth}|p{0pt}}
     \centering A &  \centering B &\\
     \raggedleft C & \raggedright D &\\ 
\end{tabular}

Answer 3

Not all extra alignment tab has been changed to \cr errors are found via Google or Bing. Something as simple as defining a macro with arguments and forgetting the argument before the first \\ will reproduce the error.

Same thing with \newcommand.

e.g.,

\def\test#1#2{$\hbox to 4cm{#1}}$}
\begin{tabular}{cccc}
Oh & \test{tested}{} & Oh & \test{Oh} \\
   & \test{testing}{} &   & \test{Ohh}{} \\
\end{tabular} 

Answer 4

Hi，I had the same question and googled to this page. At last, I solved this problem by add one more c, the correct case should like below:

\documentclass{article}

\begin{document}

\begin{tabular}{c|c|c}
one & two & three \\
\hline
one & two 
\end{tabular}
\end{document}

Answer 5

Here's another way you can get this error (the error is still that there are too many columns, but if you're as stupid as I am that isn't obvious):

I was using && instead of & for some reason. So I had twice as many columns as I thought. I couldn't figure out what was wrong for a long time, because all the answers here said "this error is caused by having too many columns!" and I was like, "I don't have too many columns!".

So if anyone out there shares my && disability, hopefully this answer will help you :)

Answer 6

Another possible reason is using a \cline{2-3} with {2-3} defining which columns need to be covered by the line. If you have less columns (here: less than 3) than you define in the \cline command, you get this error.

Example with error:

\begin{table}[]
\centering
\caption{My caption}
\label{my-label}
\begin{tabular}{ll}
\hline
\textbf{Column 1} & \textbf{Column 2} \\ \hline
Content           & Content           \\ \cline{2-3} % <-- this causes the error
Content           & Content           \\ \hline
\end{tabular}
\end{table}

Example without error:

\begin{table}[]
\centering
\caption{My caption}
\label{my-label}
\begin{tabular}{ll}
\hline
\textbf{Column 1} & \textbf{Column 2} \\ \hline
Content           & Content           \\ \cline{2-2}
Content           & Content           \\ \hline
\end{tabular}
\end{table}

Answer 7

An alternative solution with tblr environment of tabularray package: the number of columns is determined by table contents.

\documentclass{article}

\usepackage{tabularray}

\begin{document}

\begin{tblr}{}
One & Two & Three & Four & Five & Six & Seven & Eight & Nine & Ten \\
One & Two & Three & Four & Five & Six & Seven & Eight & Nine & Ten \\
\end{tblr}

\bigskip

\begin{tblr}{hlines,vlines}
One & Two & Three & Four & Five & Six & Seven & Eight & Nine & Ten \\
One & Two & Three & Four & Five & Six & Seven & Eight & Nine & Ten \\
\end{tblr}

\end{document}

Answer 8

For anyone arriving at this error NOT coming from working in a tabular environment, make sure that you aren't using an "&" without escaping it. E.g. you should be using Salt \& Pepper rather than Salt & Pepper.