If I use
\begin{itemize}
\item asdasd
\item dsfsdf
\end{itemize}
the items are with a bullet, but how can I itemize these two with a "-" (a dash / a hyphen / a small line)?
If I use
\begin{itemize}
\item asdasd
\item dsfsdf
\end{itemize}
the items are with a bullet, but how can I itemize these two with a "-" (a dash / a hyphen / a small line)?
One-at-a-time method:
\begin{itemize}
\item[--] asdasd
\item[--] dsfsdf
\end{itemize}
Set all first-level bullet-point to --:
At preamble, in plain-TeX
\def\labelitemi{--}
or in LaTeX
\renewcommand\labelitemi{---}
These have the same effect, but if you want all your definitions to look similar you can prefer one over the other.
Set the first-level bullet-point to -- only in one itemize environment:
\begin{itemize}
\renewcommand\labelitemi{--}
\item asdasd
\item dsfsdf
\end{itemize}
\item[-].
–
Mar 13 '10 at 15:35
\renewcommand\labelitemi{---} available in beamer as well? I'm getting error for missing command.
– CKM
Aug 17 '19 at 17:32
For reference, here's a package-wise approach using the (de-facto) list manipulation package, enumitem:

\documentclass{article}
\usepackage{enumitem}% http://ctan.org/pkg/enumitem
\begin{document}
\begin{itemize}[label={--}]
\item asdasd
\item dsfsdf
\end{itemize}
\end{document}
\setlist[⟨names⟩,⟨levels⟩]{⟨keys/values⟩}. See the enumitem documentation. I have an answer here that gives some settings I like in a beamer presentation.
– T. Zack Crawford
Apr 13 '21 at 19:37
% before \begin{document}
\usepackage{enumerate}
% after \begin{document}
\begin{enumerate}[-]
\item asdasd
\item dsfdsf
\end{enumerate}
Ideally, the enumerate package is already in MiKTeX so you need not download it.
{} button in the edit window or by indenting the code by four blank spaces.
– Peter Jansson
Feb 28 '13 at 11:14
enumerate is a latex “required” package; a distribution that doesn't contain it is non-conforming. so idealism ought not to be required...
– wasteofspace
Feb 28 '13 at 14:55
The alternative solution for whole document/representation:
\usepackage{enumitem}
\setlist[itemize]{itemsep=10pt, label={--}}
\setlist[itemize]{...}. The command \setitemizewas deprecated 8 years ago.
– Javier Bezos
Mar 21 '19 at 14:19
A much better looking results are obtained if one uses math minus symbol instead of en-dash:
\begin{itemize}
\item[$-$] asdasd
\item[$-$] dsfsdf
\end{itemize}
Use package enumitem with parameter shortlabels:
\documentclass{article}
\usepackage[shortlabels]{enumitem}
\begin{document}
Remember use ``shortlabels'' parameter
\begin{itemize}[-]
\item aaa
\item bbb
\end{itemize}
\end{document}
To use bold dash, replace [-] by [\textbf{-}]; or longer dash, replace [-] by [--]. To use +, replace [-] by [+].