in reply to Using Split to load a hash

I am wondering if we can load a HOA in a similar way. I have always used the following: 
use strict;
use Data::Dumper;

my %hash;
while(<DATA>)
{
    chomp;
    my $line = $_;
    my $key = (split/\t/, $line)[0];
    
    push @{ $hash{$key} }, $line;
    
}
print Dumper(\%hash);

__DATA__
1    a    101
1    b    110
2    c    201
3    d    301
3    e    310
3    f    320
4    g    401

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Re^2: Using Split to load a hash
by umasuresh (Hermit) on Apr 30, 2010 at 17:33 UTC
    Following the hint in http://www.perlmonks.com/?node_id=564943,
    I tried the following with map and grep: 
    use strict;
use Data::Dumper;

my ($hash, @array);
my @array = <DATA>;  


$hash ={ map 
            { chomp; my $key = (split(/\t/) )[0]; 
            $key => [ 
                    grep {
                            chomp; $_ 
                            if( (split(/\t/) )[0] =~/$key/) 
                        } @array 
                    ]  
            } @array 
        };

print Dumper(\%$hash);

__DATA__
1    2    a
1    13    w
1    20    c
2    1    b
2    40    n
3    30    a

    [download]
    Note: DATA should be tab delimited for this to work
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