chen li am Dienstag, 26. September 2006 15:52:
> Hi all,
Hi chen
> I see some codes as following
>
> my $regexp= "(([gatc]{3})\\2{3,})";
Single quotes would make the double slash unnecessary:
my $regexp= '(([gatc]{3})\2{3,})';
[...]
> What is the meaning of {3,} of in \2{3,} ?
>
> I know \2 i
chen li <[EMAIL PROTECTED]> asekd:
> I see some codes as following
>
> my $regexp= "(([gatc]{3})\\2{3,})";
>
> my $string=~/$regexp/;
>
> What is the meaning of {3,} of in \2{3,} ?
The previous element is repeated thrice or more often.
The general syntax is {n,m} where the previous element is
--- Thomas Bätzler <[EMAIL PROTECTED]> wrote:
> chen li <[EMAIL PROTECTED]> asekd:
> > I see some codes as following
> >
> > my $regexp= "(([gatc]{3})\\2{3,})";
> >
> > my $string=~/$regexp/;
> >
> > What is the meaning of {3,} of in \2{3,} ?
>
> The previous element is repeated thrice or m
> Check perldoc perlre, "Regular Expressions":
>
> " The following standard quantifiers are
> recognized:
>[...]
>{n}Match exactly n times
>{n,} Match at least n times
>{n,m} Match at least n but not more than
> m times
> "
>
> "\2{3,}"
