Missing } inserted, Missing { inserted

Question

I created a new command to format a title and some paragraphs into a table style layout (I'm calling it a boombox).

The boombox command is:

\belowcaptionskip=-10pt
\setlength\arrayrulewidth{1pt}
\renewcommand\arraystretch{1.5}
\newcolumntype{I}{!{\vrule width 3pt}}
\newcommand\boombox[2]{
\begin{table}[H]
    \begin{tabular}{|Ip{5.67in}I|}
        \hhline{|t:=:t|}
        {#1} \\ \hhline{|:=:|}
        {#2} \\ \hhline{|b:=:b|}
    \end{tabular}
\end{table}}

I then call it out in the document:

\boombox{This is the title of the table}
        {This houses the 4 paragraphs I'm writing with \\ in between each one}

I am getting the two errors stated in the title of this post and I'm not sure why. Is it something to do with the paragraphs spanning multiple lines in the code?

Any help would be greatly appreciated!

Answer 1

You need no table environment.

The error is in bracing #1 and #2:

\documentclass{article}
\usepackage{array,hhline}

\newcolumntype{I}{!{\vrule width 3pt}}
\renewcommand\arraystretch{1.5}

\newcommand\boombox[2]{%
  \par\noindent
  \begin{tabular}{|Ip{5.67in}I|}
  \hhline{|t:=:t|}
  #1 \tabularnewline \hhline{|:=:|}
  #2 \tabularnewline \hhline{|b:=:b|}
  \end{tabular}%
}

\begin{document}

\boombox{This is the title of the table}
        {This houses the 4 paragraphs I'm writing with \\ in between each one}

\end{document}