Dear Perlmonks,

I would like to delete hash keys that are a substring of other hash keys.

My data looks like this:

this is a test => 2
is a test => 2
a test => 1

[download]

I get this data from an array in which I count the unique elements and put them in a hash, counting the number of occurrences:

sub count_unique {
 # extract unique elements of array and count occurrences
 my @array = @_;

 map { $count{$_}++ } @array;
 map { "$_ = ${count{$_}}\n"} sort keys(%count);

 return %count;
}

[download]

I then sort the hash by the string length of the key, decreasingly:

sub hashValueDescendingNum {
 # sort hash by key length in descending order
 length($a) <=> length($b)
}

[download]
Where I'm stuck is when I try to find out if element+1 is a substring of the current element. In the example below, a loop should remove everything except 'this is a test'.

this is a test => 2
is a test => 2
a test => 1

[download]

I though of getting the hash's size and then doing a for $i loop inside it, but that's as far as I got.

Thanks in advance for your help.

Larry

In reply to hash substrings by perlcat

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