Re: Merging two data sets

[InfiniteSilence]

Think in the following order,

• Description of problem
• Data structures to hold data
• Relevant operations on those data structures to perform the desired operation/processing

#!/usr/bin/perl -w
use strict;
 
my %file1hash;

my ($fin1, $fin2) = qw|alpha.dat beta.dat|;

open (DAT1,"$fin1");

while(my $line=<DAT1>) {
    chomp($line);
        next if $line=~m/^id/;
    my ($id,$x1,$x2)=split(' ' ,$line);
    push @{$file1hash{$id}}, "$x1 $x2";
}

close DAT1;

open (DAT2,"$fin2");
while (my $line=<DAT2>) {
    chomp($line);
        next if $line=~m/^id/;
    my ($id,$word)=split(' ', $line);
        if (exists $file1hash{$id}) {
        for my $x (@{$file1hash{$id}}){
                print qq|$id\t$x\t$word\n|;
        }
    }
}
close DAT2;

Makes..

A    12 45    hello
A    10 12    hello
A    15 74    hello
B    23 15    goodbye
D    19 10    happy
D    11 12    happy
E    14 5    black
E    34 31    black
C    11 41    blue
C    18 12    blue

Analysis: Your code was creating a hash with simple elements when what you really wanted was a hash of array references (incorrect choice of data structure). When you have > 1 element you can iterate over them and get them all.