Hi, Monk

I have 4 related files and my main objective is to look for common elements in all the four files. I would like to use Hash of hashes here and then include the common elements in other common hash table. For example:

Elements in File1:
1. Hi
2. March
3. Aug
4. Sept
5. Oct

Elements in File2:
1. March
2. Hi
3. Bye
4. Aug
5. Dec

Elements in File3:
1. Hi
2. March
3. Aug
4. Sept
5. Oct

Elements in File4:
1. Hi
2. March
3. Aug
4. Bye
5. Dec

[download]

Here is my code

my hoh;
my hash;

for(my $i = 0; $i <= 3; $i++){

my $condition = "first" if ($i == 0);
$condition = "second" if ($i == 1);
$condition = "third" if ($i == 2);
$condition = "forth" if ($i == 3);

## Reading the file
open my $IN, $i.".txt or die $!;
while(<$IN>){
chomp($_);
my $ele = $_;
$hoh{$i}{$_} = 1;
### Look for that element if it exists in $hoh{$i}{$_} if $i >=1 for a
+ll $i

## for the first file
if (!exists $hash{$_}){
$hash{$_} = 10**$i;
}
elsif ($i >= 1){
#### code to check the common element in all $i
#### if the common element is present then
my val = $hash{$_}
my newVal = int($val) + 10**$i; 
$hash{$_} = newVal;
}
}
close($IN);
}

[download]

I am trying to look for common elements among all the files. Say, if an element is present in all the three file and forth then it should not be counted among the common elements. Therefore my result %hash should have only March, Hi and Aug.

In reply to Hash of hashes: Check if the element is present in previous hash table by snape

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