[Tex/LaTex] the canonical way to redefine the \emph command

Question

Question says it all. What is the best way to redefine the \emph command to be bold font and upright?

Answer 1

Since \emph uses \em, I would redefine \em.

Here's such a redefinition which preserves the ability to toggle between bold and normal, if nested:

\makeatletter
\DeclareRobustCommand{\em}{%
  \@nomath\em \if b\expandafter\@car\f@series\@nil
  \normalfont \else \bfseries \fi}
\makeatother

Test of nesting behavior of \emph:

Question: \emph{What is the way to redefine the \emph{\textbackslash emph} command?}