Re: A challenging problem in perl regular expression

What makes it hard to do in a regexp is that "JAZJ" is not "JAZZ", yet you don't want to replace it. This is not the job of a regexp.

Two ways:

s/
   .
   (?<!J(?=AZZ))
   (?<!JA(?=ZZ))
   (?<!JAZ(?=Z))
   (?<!JAZZ)
/a/xgs;
[download]

s/~/a/g;
s/JAZZ/~/g;
s/[^~]/a/g;
s/~/JAZZ/g;
[download]

s/(JAZZ|.)/$1 eq 'JAZZ' ? $1 : 'a'/egs;
[download]

s/(JAZZ)|./defined($1) ? $1 : 'a'/egs;
[download]

Update: Or more.

Comment on Re: A challenging problem in perl regular expression Select or Download Code

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Re^2: A challenging problem in perl regular expression by yai (Initiate) on Jan 08, 2009 at 02:05 UTC
ikegami, thanks a lot. but the last one doesn't work if there is more than 1 'JAZZ' in a string. I tried on "JAZZxxxxJAZZ" but the result was "JAZZaaaaaaaa".	[reply]
Re^3: A challenging problem in perl regular expression by ikegami (Patriarch) on Jan 08, 2009 at 02:14 UTC
It does work if there's more than one 'JAZZ' in the string, but it doesn't work if there's one at the end of the string. Scratch that one. The best test case is probably "`JAZZxxJAZZJAZZxxJAZJAZZxxJAZZ`"	[reply] [d/l]