Changing numbering of chapters, sections and subsections in table of contents

Question

I need to build a table of contents in latex, where the chapters are as roman numerals, sections are arabic numbers, and the subsections are letters. I also need it to only go up to the subsection level.

It should look like this:

I. CHAPTER
II. CHAPTER
   1. Section
   2. Section
      (a) Subsection
      (b) Subsection

I use the following command to generate the table of contents but It does it with another format.

\tableofcontents

How do I achieve this with latex?

Ted.

Answer 1

You can redefine the commands \thechapter, \thesection, \thesubsection which control the representation of the counters for chapters, sections, and subsections. The tocloft package can be then used to add the dots:

\documentclass{book}
\usepackage{tocloft}

\renewcommand\cftchapaftersnum{.}
\renewcommand\cftsecaftersnum{.}

\renewcommand\thechapter{\Roman{chapter}}
\renewcommand\thesection{\arabic{section}}
\renewcommand\thesubsection{(\alph{subsection})}

\begin{document}

\tableofcontents

\chapter{Test Chapter One}
\section{Test Section One}
\section{Test Section One}
\subsection{Test Subsection A}
\subsection{Test Subsection B}

\end{document}

Some other adjustments might be necessary, to prevent the chapter number from overlapping the title, and perhaps reducing the space between the section number and their titles; those adjustments can be something like:

\renewcommand\cftchapnumwidth{2.8em}
\renewcommand\cftsecnumwidth{2em}
\renewcommand\cftsecindent{3em}
\renewcommand\cftsubsecindent{5em}