Jim Gibson wrote: > On 11/24/09 Tue Nov 24, 2009 4:42 PM, "Orchid Fairy (兰花仙子)" > <practicalp...@gmail.com> scribbled: > >> On Wed, Nov 25, 2009 at 8:38 AM, Shawn H Corey <shawnhco...@gmail.com> wrote: >> >>> It seems to be picking up an extra empty string after a non-zero length >>> match. >>> >> Thanks John and Shawn. >> Yup what let me be confused is that, why there is an additional empty >> string there? > > You get 4 matches because there are four places in the string 'aXXXb' that > can be matched by 'X*'. Note that a "place" in this case is a position > between characters. The places are: > > 1. before the a > 2. after the a > 3. before the b > 4. after the b
Funny, I get this on my machine: $ perl -le '$_="aXXXb"; print "one word is $1 at ", pos while(/(X*)/g);' one word is at 0 one word is XXX at 4 one word is at 4 one word is at 5 That is: 1. before the a 2. between the a and b 3. before the b 4. after the b The problem is that the third one should not be there. Consider: $ perl -le '$_="ab"; print "one word is $1 at ", pos while(/(X*)/g);' one word is at 0 one word is at 1 one word is at 2 This looks better. Why does another one appear when the XXX should only replace the second empty string? -- Just my 0.00000002 million dollars worth, Shawn Programming is as much about organization and communication as it is about coding. I like Perl; it's the only language where you can bless your thingy. -- To unsubscribe, e-mail: beginners-unsubscr...@perl.org For additional commands, e-mail: beginners-h...@perl.org http://learn.perl.org/
