Uppercase sections and subsections on ToC

Question

How can I insert \MakeUppercase inside the table of contents for sections and subsection?

\renewcommand{\l@section}[2]%
{\@dottedtocline{1}{.5em}{1.3em}%
 {{\bfseries\selectfont#1}}{#2}}

Answer 1

This is a fairly general approach for changing the appearance of the entries in the table of contents.

The patch with \xpatchcmd* is just a way for avoiding copying the definition from latex.ltx and modifying it. The two places where #7 appears in \addtocontents are replaced by \@nameuse{format#1}{#7} so we can define \formatsection and so on to do what we want to the title in the TOC.

\documentclass{article}

%%% Patching the kernel \@sect command
\usepackage{regexpatch}
\makeatletter
\xpatchcmd*{\@sect}{\fi#7}{\fi\@nameuse{format#1}{#7}}{}{}

%%% for sections and subsections we want uppercase
\protected\def\formatsection{\MakeUppercase}
\protected\def\formatsubsection{\MakeUppercase}

%%% the other titles are left unchanged
\let\formatsubsubsection\@firstofone
\let\formatparagraph\@firstofone
\let\formatsubparagraph\@firstofone

%%% the following is necessary only if hyperref is used
\AtBeginDocument{%
  \pdfstringdefDisableCommands{%
    \let\formatsection\@firstofone
    \let\formatsubsection\@firstofone
  }%
}
\makeatother

\usepackage{hyperref}

\setcounter{secnumdepth}{3}

\begin{document}

\tableofcontents

\section{This is a section}

\subsection{This is a subsection}

\subsubsection{This is a subsubsection}

\end{document}