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PHP function implements method of extracting keywords from a text string_PHP tutorial

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2016-07-13 09:47:59768browse

PHP function implements the method of extracting keywords from a text string

This article describes the example of the PHP function implementing the method of extracting keywords from a text string. Share it with everyone for your reference. The specific analysis is as follows:

This is a function positioning that receives a string as a parameter (together with other configuration optional parameters), and positions all keywords in the string (the words with the most occurrences), returning an array or a string separated by commas keyword. The functionality works fine, but I'm improving it, so interested friends can suggest improvements.

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/**

* Finds all of the keywords (words that appear most) on param $str

* and return them in order of most occurrences to less occurrences.

* @param string $str The string to search for the keywords.

* @param int $minWordLen[optional] The minimun length (number of chars) of a word to be considered a keyword.

* @param int $minWordOccurrences[optional] The minimun number of times a word has to appear

* on param $str to be considered a keyword.

* @param boolean $asArray[optional] Specifies if the function returns a string with the

* keywords separated by a comma ($asArray = false) or a keywords array ($asArray = true).

* @return mixed A string with keywords separated with commas if param $asArray is true,

* an array with the keywords otherwise.

*/

function extract_keywords($str, $minWordLen = 3, $minWordOccurrences = 2, $asArray = false)

{

function keyword_count_sort($first, $sec)

{

return $sec[1] - $first[1];

}

$str = preg_replace('/[^\w0-9 ]/', ' ', $str);

$str = trim(preg_replace('/s /', ' ', $str));

$words = explode(' ', $str);

$keywords = array();

while(($c_word = array_shift($words)) !== null)

{

if(strlen($c_word) <= $minWordLen) continue;

$c_word = strtolower($c_word);

if(array_key_exists($c_word, $keywords)) $keywords[$c_word][1] ;

else $keywords[$c_word] = array($c_word, 1);

}

usort($keywords, 'keyword_count_sort');

$final_keywords = array();

foreach($keywords as $keyword_det)

{

if($keyword_det[1] < $minWordOccurrences) break;

array_push($final_keywords, $keyword_det[0]);

}

return $asArray ? $final_keywords : implode(', ', $final_keywords);

}

//How to use

//Basic lorem ipsum text to extract the keywords

$text = "

Lorem ipsum dolor sit amet, consectetur adipiscing elit.

Curabitur eget ipsum ut lorem laoreet porta a non libero.

Vivamus in tortor metus. Suspendisse potenti. Curabitur

metus nisi, adipiscing eget placerat suscipit, suscipit

vitae felis. Integer eu odio enim, sed dignissim lorem.

In fringilla molestie justo, vitae varius risus lacinia ac.

Nulla portitor justo a lectus iaculis ut vestibulum magna

egestas. Ut sed purus et nibh cursus fringilla at id purus.

";

//Echoes: lorem, suscipit, metus, fringilla, purus, justo, eget, vitae, ipsum, curabitur, adipiscing

echo extract_keywords($text);

I hope this article will be helpful to everyone’s PHP programming design.

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