Regular Expressions Question

How do you use them? The difference here is that the second one has three subexpressions, while the first one only has one.

The first matches "&" when it is followed by not ("amp;" or "nbsp;").
The second matches "&" when it is followed by (not "amp;") or (not "nbsp;").

That means the second will match every "&", because it's impossible to be followed by both "amp;" and by "nbsp;" - it will always succeed either the 'not followed by "amp;"' or the 'not followed by "nbsp;"' test (or both), and the '|' just means the whole expression will match if either of those cases matches. So it's equivalent to /&/g, which isn't very useful, whereas the first will correctly match any "&" that isn't part of " " or "&".

Thank you very much for the explanation, it really helped my understanding of it . I don't have much experience with regexp, but I'm trying to learn more now; it just takes some getting used to I guess.

Regular expressions are easy. Try making a turing machine out of SED scripts.

Quote:

Original post by Wyrframe Regular expressions are easy. Try making a turing machine out of SED scripts.

try doing anything with SED :P j/k