Note inside \cite brackets, at beginning instead of end

Question

I'd like to put a note inside \cite brackets, at the beginning, like this:

[e.g. 19,20]

with the space being non-breaking.

The optional argument makes puts something at the end:

\cite[e.g.]{refA,refB}

gives

[19;, 20, e.g.]

(though there are more commas and semicolons than I would like).

Is there a package or some other magic that will achieve this?

Answer 1

The citing commands of biblatex feature a second optional argument that does what you want. Note that if you only want to add a citation prenote, you have to use both optional arguments (with the postnote argument empty).

\documentclass{article}

\usepackage{biblatex}

\usepackage{filecontents}

\begin{filecontents}{\jobname.bib}
@misc{A01,
  author = {Author, A.},
  year = {2001},
  title = {Alpha},
}
\end{filecontents}

\addbibresource{\jobname.bib}

\begin{document}

See \autocite[99]{A01}.

See \autocite[e.\,g.][99]{A01}.

See \autocite[e\,.g.][]{A01}.

\printbibliography

\end{document}