How to extract the medium letter of a word using only regex for ex.:
"someWord" -> "e" or "W" no sense
"Hello" -> "l"
"Music" -> "s"
"four" -> "o" or "u" no sense
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1What do you mean by `no sense`? – Martin Ender Oct 29 '12 at 20:52
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And why does it **have** to be regex? This would be so much easier with `substr`. – h2ooooooo Oct 29 '12 at 20:54
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In what language are you working? – alestanis Oct 29 '12 at 20:55
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I guess "no sense" means "it doesn't matter which". – Barmar Oct 29 '12 at 21:03
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If the lenght of the string can be divided by two, anyway the len/2 letter or len/2 + 1 letter will be returned – user1784032 Oct 30 '12 at 11:37
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I know, this very easy thing to do with other function.But it is strongly recomended to do with regex exp.I wait only for pattern, which use only regex and no other functions – user1784032 Oct 30 '12 at 11:40
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"In what language are you working?".For me important only the pattern with no function used – user1784032 Oct 30 '12 at 11:41
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Id does not make sense to use regex for this kind of task!
As I don't know what environmnet and language you use, I can give you just general scheme:
pattern = '^.{' + Int(Length(str)/2) + '}(.)'
or
pattern = '(?<=^.{' + Int(Length(str)/2) + '}).'
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1the fact that it does not make sense, does not really make it an invalid question I think. Trying to get to the boundaries of what's possible with regex, might give a deeper understanding of regex for reasonable applications, as well. Just like [this](http://stackoverflow.com/q/12941362/1633117) or [this question](http://stackoverflow.com/q/12715679/1633117). They are certainly not sensible for productive use, but they teach you a lot about regexes. However, I think this problem is really beyond pure regex, even using `(?R)`. – Martin Ender Oct 29 '12 at 21:04