In bash, what's the regular expression to list two types of files?

Question

A directory contains .zip and .rar files, and files of other type.

To list only .rar and .zip files, there is ls *.zip *.rar

In bash, how to match both types with one regex?

Answer 1

Do you really want a regular expression?

This uses * ("globbing") and {[...]} ("brace expansion").

$ ls *.{zip,rar}

See also this question for many, many more shortcuts.