3v4l.org

run code in 300+ PHP versions simultaneously

@ 2015-05-05T16:28:16Z

<?php
  //http://stackoverflow.com/questions/653157/a-better-similarity-ranking-algorithm-for-variable-length-strings

  class StringMatch{
    public static function compare($a, $b){
      $pairsA = self::wordLetterPairs($a);
      $pairsB = self::wordLetterPairs($b);

      $union = count($pairsA) + count($pairsB);
      $intersect = count(array_intersect($pairsA, $pairsB));
      return 2*$intersect/$union;
    }

    public static function letterPairs($str){
      $pairCount = strlen($str)-1; //don't compute every time in if
      $pairs = array();

      for($i = 0; $i < $pairCount; $i++){
        $pairs[] = substr($str, $i, 2);
      }
      return $pairs;
    }

    public static function wordLetterPairs($str){
      $allPairs = array();
      $str = explode(" ", $str);

      //get pairs in each word
      foreach($str as $w){
        $pairs = self::letterPairs($w);
        //make sure, no doubled pairs are included
        foreach($pairs as $p){
          $allPairs[$p] = $p;
        }
      }
      return array_values($allPairs);
    }
  }

  var_dump(StringMatch::compare("GutenTag Frau Fickerin", "Ficker Herr GutenTag"));

Output for 8.0.0 - 8.0.30, 8.1.0 - 8.1.28, 8.2.0 - 8.2.18, 8.3.0 - 8.3.6: float(0.7741935483870968)
Output for 5.0.0 - 5.0.5, 5.1.0 - 5.1.6, 5.2.0 - 5.2.17, 5.3.0 - 5.3.29, 5.4.0 - 5.4.45, 5.5.24 - 5.5.35, 5.6.7 - 5.6.28, 7.0.0 - 7.0.20, 7.1.0 - 7.1.25, 7.2.0 - 7.2.33, 7.3.0 - 7.3.33, 7.4.0 - 7.4.33: float(0.7741935483871)
Output for 4.4.2 - 4.4.9: Parse error: syntax error, unexpected T_STRING, expecting T_OLD_FUNCTION or T_FUNCTION or T_VAR or '}' in /in/9YSOR on line 5
Process exited with code 255.
Output for 4.3.0 - 4.3.1, 4.3.5 - 4.3.11, 4.4.0 - 4.4.1: Parse error: parse error, unexpected T_STRING, expecting T_OLD_FUNCTION or T_FUNCTION or T_VAR or '}' in /in/9YSOR on line 5
Process exited with code 255.
Output for 4.3.2 - 4.3.4: Parse error: parse error, expecting `T_OLD_FUNCTION' or `T_FUNCTION' or `T_VAR' or `'}'' in /in/9YSOR on line 5
Process exited with code 255.

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