Question

[\d-.]+ works but [\d-.]* does not. The only thing I changed is the + to * at the end.

<b>12345</b>
<b>12345-6789</b>
<i>1234.5678</i>
<tag>1234-2342346456</tag>

I tested it out here http://regexr.com?30ngn

The * means 0 or more while + means 1 or more. Does the * only work with .?

Answer 1

The * operator works fine, it’s just regexr acting funny, or it is due to your hazardous use of the - character in a regex character class. If you want to match a - character in a character class, put it at the beginning; otherwise, the regex engine may think you want to match a range (such as [A-Z]).

The fixed regex [-\d.]* works just fine at regexpal.