Re: Using regex to extract keys

use grep:

my $r = 44;
my $hash = $self->{'residues'}{$modelCount};
for my $key ( grep { /^\w$r$/ } keys %$hash ) {
    print $key."\n";
}
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Update:Yup, as abigail suggested use each for large hashes so you dont duplicate the memory needed for the keys:

my $r = 44;
my $hash = $self->{'residues'}{$modelCount};
while( my ($key, $value) = each %$hash ) {
    next if $key =~ /^\w$r$/;
    print $key."\n";
}
[download]

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Re: Using regex to extract keys by Abigail-II (Bishop) on Sep 24, 2003 at 21:17 UTC
Since the hash is given to be large, one might prefer iterating over the hash using `each` in a `while` loop. In the loop, test whether the key matches /^\w$r$/. If not, do a `next`. Abigail	[reply]
Re: Re: Using regex to extract keys by seaver (Pilgrim) on Sep 25, 2003 at 13:59 UTC
Fantastic, Thanks! I was disappointed because I was hoping that there was some inherent regex in calling a hash key, but obviously I cant do it that way. The while loop with each does the job just grand. Cheers Sam	[reply]

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