# Access the chapter/section number and the chapter/section label through variables

Often I find myself in the situation that I'd like to design how chapters and sections look. I know there are packages that help to design such things, but non of them seems to give me the option to use the chapter/section number and the label as variables (like #1, #2).

Stefan has done something close to what I want in his blog using titlesec, but I was wondering:

Is there a pure LaTeX way of accessing the number and label of chapter/sections and use those in variables while I design a pagestyle?

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All the sectioning commands are in class (book, article report etc). Search in your distribution and look for book.cls.

They are quite lengthy and they are not in one place. For example all the "name" commands can be found towards the end of the class in one place.

Here is a minimal as to how to change some of the parameters.

\documentclass[oneside]{book}
\makeatletter
\renewcommand\chaptername{chapteris}
\renewcommand \thechapter {\@Roman\c@chapter}

\renewcommand\section{\@startsection{section}{1}{\z@}%
{-3.5ex \@plus -1ex \@minus -.2ex}%
{2.3ex \@plus.2ex}%
{\normalfont\large\scshape}}

\newcommand\sectionis{\@startsection{section}{1}{\z@}%
{-3.5ex \@plus -1ex \@minus -.2ex}%
{2.3ex \@plus.2ex}%
{\normalfont\large\scshape}}

\renewcommand\appendix{\par
\renewcommand\chaptername{Appendixis}
\setcounter{chapter}{0}
\setcounter{section}{0}
\gdef\@chapaa{\appendixname}
\gdef\thechapter{\@roman\c@chapter}
}

\makeatother
\begin{document}
\tableofcontents
\chapter{My First Chapter}
\section{One}
\sectionis{Two}
\chapter{My Second Chapter}
\appendix
\chapter{First Appendix}
\chapter{Second Appendix}
\end{document}

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Thank you, I am however aware of those definitions. but the problem is, the definitions as in e.g. section ..{\normalfont\large\scshape}. Say I'd like to do something like \hspace{dim} section title \hspace{dim}, this is notpossible with this commands, is it? –  Martin H Feb 16 '11 at 9:51
If you really want this \hspace{dim}, you can use, for example : \def\@seccntformat#1{% \hspace*{<dim>}\protect\makebox[0pt][l]{\csname the#1\endcsname\quad}\hspace*{<otherdim>}% } –  Jhor Jul 13 '13 at 19:09
The current values are stored in the counters chapter, section, etc., so \thechapter gives you the formatted number and \arabic{chapter} always gives you the number, \roman{chapter} in roman numerals etc. (As Martin points out, \value{chapter} will contain the value as a "proper number".)
The titles... they might be in \leftmark and \rightmark, but that depends on the document class.
You could add \value{chapter} which give the chapter number as, yeah, number, i.e. numeric expression usable in calculations. –  Martin Scharrer Feb 14 '11 at 14:09