How to add a dot after the section number?

Question

I wonder is there any way to change the format of section numbering from 1.1 to 1.1. ? I know this is trivial, but I really need to add one more dot after the section number. Does anybody know how to do that?

Thanks a lot

Answer 1

You can do this simply with the titlesec package:

\usepackage{titlesec}
\titlelabel{\thetitle.\quad}

Answer 2

It depends on what you wish precisely. If you want that in all places the section number appears as "1.1.", also in cross references, the question is settled quite easily:

\renewcommand{\thechapter}{\arabic{chapter}.}
\renewcommand{\thesection}{\thechapter\arabic{section}.}

(in this case you would also change chapter numbers, for uniformity).

If you want only the number in the section title to be followed by a period, then you can follow Alan's good suggestion or delve into the internals (see the FAQ entry for more information):

\makeatletter
\renewcommand{\@seccntformat}[1]{\csname the#1\endcsname.\quad}
\makeatother

This will change the format of all the sectional units also below \section. You might prefer the titlesec way to get more control on the appearance of the section headings.

Answer 3

If you use Komascript you may use the option numbers=endperiod.

Example:

\documentclass[11pt,english,numbers=endperiod]{scrartcl}
\usepackage{babel}
\usepackage{blindtext}

\begin{document}
\tableofcontents
\blinddocument
\end{document}

Answer 4

You can use the secdot package:

\documentclass{report}
\usepackage{secdot}
\begin{document}
\chapter{Chapter}
\section{Section}
\end{document}

Answer 5

Here's a solution that uses the low-level LaTeX macro called \@seccntformat. The main difference to egreg's answer is that it allows individual control over the formatting of the numbers associated with section, subsection, subsubsection, paragraph, and subparagraph headers. In the following example, section- and subsection-level numbers get a dot appended, whereas subsubsection-level numbers and beyond do not.

\documentclass{article}

% Method proposed in "The LaTeX Companion", 2nd ed.:
\makeatletter
\def\@seccntformat#1{\@ifundefined{#1@cntformat}%
   {\csname the#1\endcsname\space}%    default
   {\csname #1@cntformat\endcsname}}%  enable individual control
\newcommand\section@cntformat{\thesection.\space}       % section-level
\newcommand\subsection@cntformat{\thesubsection.\space} % subsection-level
\makeatother

\usepackage[colorlinks]{hyperref} % just for this example
\usepackage{cleveref}             % just for this example

\begin{document}
\section{First section} \label{sec:uno}
\subsection{First subsection} \label{sec:uno_uno}

Cross-references to \cref{sec:uno,sec:uno_uno} now look good.
\end{document}