如何使用 JavaScript 实现 Levenshtein 距离算法？

/* 如何使用 JavaScript 实现 Levenshtein 距离算法？ */
function levenshteinDistance(str1, str2) {
  var len1 = str1.length,
    len2 = str2.length,
    dif = [],
    temp;
  for (var i = 0; i <= len1; i++) {
    dif[i] = [i];
  }
  for (var j = 0; j <= len2; j++) {
    dif[0][j] = j;
  }
  for (var i = 1; i <= len1; i++) {
    for (var j = 1; j <= len2; j++) {
      temp = str1.charAt(i - 1) === str2.charAt(j - 1) ? 0 : 1;
      dif[i][j] = Math.min(dif[i - 1][j - 1] + temp, dif[i][j - 1] + 1, dif[i - 1][j] + 1);
    }
  }
  return dif[len1][len2];
}