Subsection numbering should be arabic (1.1, 1.2 etc) not A B C

Question

My sections are numbered arabic. I want to get subsection numbering also arabic as 1.1, 1.2, 1.3 etc. I have searched many forums and got these codes but it does not work for me. People say it works for us. I am using this code.

\def\thesection{\arabic{section}}
\def\thesubsection{\arabic{section}.\arabic{subsection}}
\def\thesubsubsection{\arabic{section}.\arabic{subsection}.\arabic{subsubsection}}

Only the first instruction works. I also used \renewcommand instead of \def.

Answer 1

There are classes that use \Alph for subsections. Example revtex4-1:

\documentclass{revtex4-1}

\begin{document}
\tableofcontents
\section{Section}
\subsection{Subsection}
\subsubsection{Subsubsection}
\end{document}

However, redefining the counter macro \the<counter> usually works as expected:

\documentclass{revtex4-1}

\makeatletter
\renewcommand*{\thesection}{\arabic{section}}
\renewcommand*{\thesubsection}{\thesection.\arabic{subsection}}
\renewcommand*{\p@subsection}{}
\renewcommand*{\thesubsubsection}{\thesubsection.\arabic{subsubsection}}
\renewcommand*{\p@subsubsection}{}
\makeatother

\begin{document}
\tableofcontents
\section{Section}
\label{sec}
\subsection{Subsection}
\label{subsec}
\subsubsection{Subsubsection}
\label{subsubsec}
References: \ref{sec}, \ref{subsec}, and \ref{subsubsec}.
\end{document}