[thelist] Regular Expression - Is it a bug or am I missing something very obvious?
Jeffery To
jeffery.to at gmx.net
Thu Mar 10 03:50:07 CST 2005
It's matching what you're telling it to match:
'</p>'.match(/<\/?(?!p)/) returns '<' because the string '<' contains
the character '<', zero occurrences of the character '/' and is not
followed by the character 'p' in the source string. (It is followed by
the character '/'.)
HTH,
Jeff
VOLKAN ÖZÇELİK wrote:
> Hi Community, hi RegExp lovers!
>
> Regarding the following js reg exp.
>
> /<\/?(?!(p))/ig; (It's a simplified version of what I'm working on)
>
> I think what it is supposed to do is:
>
> 1. match character < literally
> 2. match craracter / literally (zero or one times)
> 3. If there is a p immediately after do not match anything, just
> rollback (i.e. negative lookahead)
>
> so the code below
>
> var strTest1 = "</p>";
> var regEx1 = /<\/?(?!(p))/ig;
> strTest1 = strTest1.replace(regEx1,"")
> alert(strTest1);
>
> should alert "</p>".
> Well it doesn't. It alerts "p/>". Which means that it has found a match.
>
> I need to swap things around to make it work:
>
> var strTest2 = "</p>";
> regEx2 = /<(?!(\/p|p))/ig;
> strTest2 = strTest2.replace(regEx2,"")
> alert(strTest2);
>
> but why on earth do I need to make things unnecessarily complicated ?!
> The first one should work at least according to my humble logic!
>
> Is it a bug? Or am I missing a really simple thing?
>
> Please help me before I split this PC with an axe.
>
> TIA,
> Volkan.
More information about the thelist
mailing list