Levenshtein JavaScript

levenshtein.js

var levenshtein = function(str1, str2) {
    str1 = str1.split("");
    str2 = str2.split("");
    var distance = [],
        l = str1.length,
        m = str2.length,
        i, j;

    for( i = 0; i <= l; i++ ) {
        distance[i] = [i];
    }
    for( j = 0; j <= m; j++ ) {
            distance[0][j] = j;
    }
    for( i = 1; i <= l; i++ ) {
        for( j = 1; j <= m; j++ ) {
            distance[i][j] = Math.min( distance[i-1][j]+1, distance[i][j-1]+1, distance[i-1][j-1]+
                                    ((str1[i-1]==str2[j-1])?0:1) );
        }
    }
    return distance[l][m];

};
    
alert(levenshtein('dog', 'fog'));
alert(levenshtein('feet', 'foot'));
alert(levenshtein('foot', 'fleet'));