PHP Extract Most Used Words in a String or Paragraph

Here is a neat little PHP function that pulls out the most common words from a string and ranks them based on frequency used. A preset list of words in an external .txt file provide the “skip word” reference, meaning they are not counted as a common occurrence. This prevents the, a, and etc from showing up.

To call the function:

$variable = extractWords( $your_txt_string, $stop_words);

1	$variable = extractWords( $your_txt_string, $stop_words);

The function:

function extractWords($string, $stop_words, $max_count = 5){  //max count to define how many words are returned
	  
      $string = preg_replace('/\s\s+/i', '', $string); // replace whitespace
      $string = trim($string); // trim the string
      $string = preg_replace('/[^a-zA-Z.\/\&nbsp\;() - ]/', '', $string); // only take alpha characters, but keep the spaces and dashes too… remove / . 
      $string = strtolower($string); // make it lowercase
      $string = strip_tags($string);
   
      preg_match_all('/\b.*?\b/i', $string, $matchWords);
      $matchWords = $matchWords[0];
      
      foreach ( $matchWords as $key=>$item ) {
      	  if ( $item == '' || in_array($item, $stop_words) || strlen($item) <= 3 ) {
              unset($matchWords[$key]);
          }
      }   
      $wordCountArr = array();
      if ( is_array($matchWords) ) {
          foreach ( $matchWords as $key => $val ) {
              $val = strtolower($val);
              if ( isset($wordCountArr[$val]) ) {
                  $wordCountArr[$val]++;
              } else {
                  $wordCountArr[$val] = 1;
              }
          }
      }
      arsort($wordCountArr);
      $wordCountArr = array_slice($wordCountArr, 0, $max_count);
      return $wordCountArr;
}

function extractWords($string, $stop_words, $max_count = 5){ //max count to define how many words are returned

$string = preg_replace('/\s\s+/i', '', $string); // replace whitespace

$string = trim($string); // trim the string

$string = preg_replace('/[^a-zA-Z.\/\&nbsp\;() - ]/', '', $string); // only take alpha characters, but keep the spaces and dashes too… remove / .

$string = strtolower($string); // make it lowercase

$string = strip_tags($string);

preg_match_all('/\b.*?\b/i', $string, $matchWords);

$matchWords = $matchWords[0];

foreach ( $matchWords as $key=>$item ) {

if ( $item == '' || in_array($item, $stop_words) || strlen($item) <= 3 ) {

unset($matchWords[$key]);

}

$wordCountArr = array();

if ( is_array($matchWords) ) {

foreach ( $matchWords as $key => $val ) {

$val = strtolower($val);

if ( isset($wordCountArr[$val]) ) {

$wordCountArr[$val]++;

} else {

$wordCountArr[$val] = 1;

}

arsort($wordCountArr);

$wordCountArr = array_slice($wordCountArr, 0, $max_count);

return $wordCountArr;

}

The text file for stop_words.txt is just a list of words and common phrases. To include the .txt file use this line of PHP somewhere in your page:

$stop_words = file('inc/stop_words.txt', FILE_IGNORE_NEW_LINES | FILE_SKIP_EMPTY_LINES);

1	$stop_words = file('inc/stop_words.txt', FILE_IGNORE_NEW_LINES \| FILE_SKIP_EMPTY_LINES);

stop_words.txt

a
able
about
above
abst
accordance
according
accordingly
across
act
actually
added
adj
adopted
affected
affecting
affects
...
....
(add as many as needed to suit your use)

able

about

above

abst

accordance

according

accordingly

across

act

actually

added

adj

adopted

affected

affecting

affects

...

....

(add as many as needed to suit your use)

If you wanted to show the results in a comma separated list you could use something like the below:

echo implode(',', array_keys($variable))

1	echo implode(',', array_keys($variable))

Lekker Logic
Tags: functions, PHP, Programming, Snippet, Web

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PHP Extract Most Used Words in a String or Paragraph

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