Re: count characters in a string

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count characters in a string

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Join Date: Mar 2006

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KevinADC

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Re: count characters in a string

#30

Apr 14th, 2008

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Originally Posted by godevars

Still learning on my end.
I am reviewing the code and am trying to understand this:

$cnter{$_}{$title}++ for @line;

I see this as a hash, %cnter, being populated . $_ is the word and the $title is the section. I see that the keys = $_ in this loop which are all the words. The value would then be the $title and the ++ is to count each individual word appearing in the section. Is the 'for @line' portion used for reading each line as it comes through?

I think this means this code already has a hash of all the words in each section: keys %cnter. I am tryin to figure out how to detemrine how to identify the hash for each section.

Thanks-

%cnter is a two dimensional hash ( a hash of hashes). $_ (the words) and $title (the section title) are bot hash keys. The value of a hash key can be another hash (and more things besides). ++ is the count of each word per section.

'for @line' just loops through the @line array and applies the value of each "line" to $_ which is used to build the hash up with. Its a short way of writing:

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for (@line) {
    $cnter{$_}{$title}++;
}

It does mean there is a hash with all the words counted per all sections.

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%cntr = (
word1 => {
    title1 => count,
    title2 => count,
 },
word2 => {
    title1 => count,
    title2 => count,
 } 
etc etc

If a word was not found in a section it would not be in the word hash. This is why my code checks later all the section titles and applies a value of 0 (zero) if a word was not found in a particular section.

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