levenshtein() - string

The Levenshtein distance is defined as the minimal number of
   characters you have to replace, insert or delete to transform
   str1 into str2.
   The complexity of the algorithm is O(m*n),
   where n and m are the
   length of str1 and
   str2 (rather good when compared to
   similar_text(), which is O(max(n,m)**3),
   but still expensive).

Parameters : 
 str1 - One of the strings being evaluated for Levenshtein distance. 
 str2 - One of the strings being evaluated for Levenshtein distance. 
 cost_ins - Defines the cost of insertion. 
 cost_rep - Defines the cost of replacement. 
 cost_del - Defines the cost of deletion. 

Syntax

int levenshtein
    ( string $str1
   , string $str2
   )

Example

<?php// input misspelled word$input = 'carrrot';// array of words to check against$words  = array('apple','pineapple','banana','orange',                'radish','carrot','pea','bean','potato');// no shortest distance found, yet$shortest = -1;// loop through words to find the closestforeach ($words as $word) {    // calculate the distance between the input word,    // and the current word    $lev = levenshtein($input, $word);    // check for an exact match    if ($lev == 0) {        // closest word is this one (exact match)        $closest = $word;        $shortest = 0;        // break out of the loop; we've found an exact match        break;    }    // if this distance is less than the next found shortest    // distance, OR if a next shortest word has not yet been found    if ($lev <= $shortest || $shortest < 0) {        // set the closest match, and shortest distance        $closest  = $word;        $shortest = $lev;    }}echo "Input word: $input\n";if ($shortest == 0) {    echo "Exact match found: $closest\n";} else {    echo "Did you mean: $closest?\n";}?>

Output / Return Value

Limitations

Alternatives / See Also

Reference