Question

I have a bunch of LI elements for which I need to change the ID names of.

Example target text I would search:

<li id="apple">blah blah blah</li>
<other stuff>
<li id="bacon">blah blah blah</li>

I would want to find just the part that says:

<li id="idnamehere"

I tried using this line of code in JavaScript:

myRegExp = new RegExp('<li id="[^"]*+"', "g");

However I get this error:

"SyntaxError: Invalid regular expression: nothing to repeat"

When I try this expression in a regular expression editor, it works fine. Any ideas as to what’s going wrong?

Answer 1

there is no entity for the + to repeat. decide if you want to use + or *, i.e. (i removed the escapes)

<li id="[^"]+"

to match one-or-more-character-ids or

<li id="[^"]*"

to match empty id, too. furthermore you don’t need explicit lazy or greedy matching if you use the unambiguous way you did: *? and * mean the same in your case, i.e. “match everything until you encounter an quotation mark.”

but generally: don’t parse XML with regular expressions, as the XML parsers built in your browser normally do a better job than you.