Accessing multiple arguments in `\newcommand` in Tikz

Question

I need a figure like this (four vertically stacked rectangles with text; the two numbers in the texts are different and don't follow a pattern):

What I did:

%working
\documentclass{standalone}
\usepackage{tikz,amsmath}
\newcommand{\vrect}[2]{ %%% Need to pass an array of 4 arguments
    \foreach \pos [count=\i] in {{(0,-4)},{(0,-3)},{(0,-2)},{(0,-1)}}{
        \node[draw=black,thick,minimum size=1cm] (z\i) at \pos {Val#1#2};
    }
}
\begin{document}
    \begin{tikzpicture}[scale=1]
    %%\vrect{{1,1}, {3,5}, {8,7}, {1,0}}} %% How to use this?
    \vrect{1}{1}
    \end{tikzpicture}

\end{document}

I don't really know

• how to pass an array as an argument
• how to access arguments based on the index (tried #\i with failure)

Any help is appreciated. P.S. I need to draw few figures like this, so I created a \newcommand.

Answer 1

The \foreach command can iterate over multiple parameters, separated by /. You can use the array of the loop as parameter for your command. The position can be set with the counter \i by (0,-\i).

Note: You can pass an arbitrary number of parameters inside the array (don't have to be 4).

\documentclass{standalone}
\usepackage{tikz,amsmath}

\newcommand{\vrect}[1]{
    \foreach \x/\y [count=\i] in #1 {
        \node[draw=black,thick,minimum size=1cm] (z\i) at (0,-\i) {Val\x\y};
    }
}

\begin{document}
    \begin{tikzpicture}[scale=1]
        \vrect{{1/1, 3/5, 8/7, 1/0}}
    \end{tikzpicture}
\end{document}

Answer 2

You can give your array as a single argument to \vect, however, it will be easier if instead of using the list {1,1}, {3,5}, {8,7}, {1,0} you instead use 1/1, 3/5, 8/7, 1/0. This way you can loop over your coordinates in the "normal" tikz fashion.

Here's your full (corrected) MWE:

\documentclass{standalone}
\usepackage{tikz,amsmath}

\newcommand{\vrect}[1]{ %%% Need to pass 4 arguments
    \foreach \x/\y [count=\i] in {#1} {
        \node[draw=black,thick,minimum size=1cm] (z\i) at (\x,\y) {Val\x-\y};
    }
}
\begin{document}
    \begin{tikzpicture}[scale=1]
      \vrect{1/1, 3/5, 8/7, 1/0} %% How to use this!
    \end{tikzpicture}
\end{document}

which produces

Notice that this will work for any number of arguments in the array.

EDIT

If you want the boxes stacked vertically this is marginally easier:

\documentclass{standalone}
\usepackage{tikz,amsmath}

\newcommand{\vrect}[1]{ %%% Need to pass 4 arguments
\foreach \x/\y [count=\i] in {#1} {
        \node[draw=black,thick,minimum size=1cm] (z\i) at (0,-\i) {Val\x-\y};
    }
}
\begin{document}
    \begin{tikzpicture}[scale=1]
      \vrect{1/1, 3/5, 8/7, 1/0} %% How to use this?
    \end{tikzpicture}
\end{document}

which produces:

Again, this will accept an arbitrary number of arguments.

Answer 3

If you're not tied to that weird syntax:

\documentclass{standalone}
\usepackage{tikz,amsmath}

\newcommand{\vrect}[1]{%
  \def\myarray{{#1}}%
  \foreach \pos [count=\i from 0] in {{(0,-4)},{(0,-3)},{(0,-2)},{(0,-1)}}{
    \pgfmathsetmacro{\val}{\myarray[\i]}%
    \node[draw=black,thick,minimum size=1cm] (z\i) at \pos {Val\val};
  }%
}
\begin{document}

\begin{tikzpicture}
\vrect{11,35,87,10}
\end{tikzpicture}

\end{document}