! Illegal unit of measure (pt inserted) with \foreach with 2 variables with this simple code

Question

I want to iterate the variable i between [1,9], with the iterations with the variable j between [3,11]

\foreach \i/\j in {1/3,...,9/11}{}

So I wrote the above code, however as I run this , the error messages with

! Illegal unit of measure (pt inserted).
<to be read again> 
                   /

appears .

What can I do next?

\documentclass[border=0.1cm]{standalone}
\usepackage{tikz}
\usepackage{mathtools}
\begin{document}
\begin{tikzpicture}[]

    \foreach \i/\j in {1/3,...,9/11}{
    \draw[-&gt;](\i,\i,0)--(\i,\j,0);
    }

\end{tikzpicture}


\end{document}

what is the desired result -- if you expand the first i/j it will result in draw 1,3,0 to 1,3,0 — js bibra, Aug 23 '21 at 04:41
have a look here -- https://tex.stackexchange.com/questions/171426/increments-in-foreach-loop-with-two-variables-tikz — js bibra, Aug 23 '21 at 04:50

score 2 · Accepted Answer · answered Aug 23 '21 at 05:44

Your code can reduce to

\documentclass[border=0.1cm]{standalone}
\usepackage{tikz}
\usepackage{mathtools}
\begin{document}
\begin{tikzpicture}[]

    \foreach \i/\j in {1,2,...,9}{
        \draw[-&gt;](\i,\i,0)--(\i,\i+2,0);
    }

\end{tikzpicture}


\end{document}

! Illegal unit of measure (pt inserted) with \foreach with 2 variables with this simple code

1 Answers1