My question is simple suppose I would like to match the vowels in a word, but I would like to match them in a specific order as the appear such as a, e, i, o, u. How would I go about doing this?
Asked
Active
Viewed 1.5k times
2 Answers
10
So you're looking for a followed by some characters, then e followed by some characters, and so forth?
In other words, a followed by stuff that isn't e, then e. Then stuff that isn't i then i. Then stuff that isn't o then o. And finally stuff that isn't u and lastly a u.
In regexp terms, that's a[^e]*e[^i]*i[^o]*o[^u]*u
(You could get by with a .*? but why do that when you can more precisely define what you mean.)
VoteyDisciple
- 37,319
- 5
- 97
- 97
-
1You forgot some *s in there, but I think anyone would udnerstand. – Seth Robertson May 20 '11 at 02:16
-
4a slight refinement would be: a[^eiou]*e[^aiou]*i[^aeou]*o[^aeiu]u – Alvin May 20 '11 at 02:26
-
So I did! Added the missing *s in. – VoteyDisciple May 20 '11 at 02:28
-
@Alvin raises an excellent point. I have assumed that any string is valid as long as the vowels exist in that order. So uAuEuIuOuUu is valid, since I can spot (and have capitalized) an A-E-I-O-U sequence, despite an abundance of extra U's. If you need to allow vowels ONLY in that order, you would need to do as Alvin suggests. – VoteyDisciple May 20 '11 at 02:32
-
@Votey your regular expressions doesn't match uAuEuluOuUu but it does match "sacrilegious' which proves your point. – Steffan Harris May 20 '11 at 03:15
-
With `/i` it will. (-: The caps were there for readability, rather than to actually distinguish them from lowercase letters. But quite right — "sacrilegious" would also match. – VoteyDisciple May 20 '11 at 12:25
0
I would go with:
a.*?e.*?i.*?o.*?u
But this has the same problem that is pointed out in a comment by Alvin to Votley's answer. This is due to the question not specified enough. It is not specified what the priority is.
sawa
- 165,429
- 45
- 277
- 381