renewcommand - add characters

Question

I replaced the \citet command by

\renewcommand{\citep}{[\citenum}

The "[" als introduces a square bracket before the citiation number, however, I couldn't figure out how to also add a closing one.

Unfortunately, my internet search was not successful.

Answer 1

I do not understand why you want to do this. With a simple \cite and the plain style you'll get the same:

\documentclass{article}
\usepackage{natbib}
\renewcommand\citep[1]{[\citenum{#1}\relax]}
\begin{filecontents*}{\jobname.bib}
@incollection{lennon1965,
        author    = {John Lennon},
        booktitle = {A book with articles},
        editor    = {Paul McCartney and John Lennon and George Harrison and Richard Starkey},
        title     = {This is my article in this book},
        year      = {1965},
        location  = {Liverpool},
        pages     = {65--87},
        publisher = {Cavern Club},
    }
\end{filecontents*}
\begin{document}
foo\citep{lennon1965} bar\cite{lennon1965}

\bibliographystyle{plain}
\bibliography{\jobname}
\end{document}

However, using biblatex instead of natbib makes more sense.