https://tex.stackexchange.com/q/551501/35864

array.tex

\documentclass{standalone}
\usepackage{calc}
\usepackage{tikz}

\begin{document}

\tikzset{
    pics/mypic/.style n args={1}{
        code={
            \foreach \i in {0,1,2}{
              \node at (\i, 0) {$\pgfmathparse{{#1}[\i]}\pgfmathresult$};
            }
        }
    }
}

\tikz{\pic at (0, 0) {mypic={"\mathtt{A}","\mathtt{B}","\mathtt{C}"};}}
\end{document}