Fast and working Levenshtein algorithm in JavaScript

We use this in our HTML5 projects for an implementation of the Levenshtein algorithm.

function levenshtein(a, b) {
 if(a.length === 0) return b.length;
 if(b.length === 0) return a.length;

 var matrix = [];

 // increment along the first column of each row
 var i;
 for(i = 0; i <= b.length; i++){
 matrix[i] = [i];
 }

 // increment each column in the first row
 var j;
 for(j = 0; j <= a.length; j++){
 matrix[0][j] = j;
 }

 // Fill in the rest of the matrix
 for(i = 1; i <= b.length; i++){
 for(j = 1; j <= a.length; j++){
 if(b.charAt(i-1) == a.charAt(j-1)){
 matrix[i][j] = matrix[i-1][j-1];
 } else {
 matrix[i][j] = Math.min(matrix[i-1][j-1] + 1, // substitution
 Math.min(matrix[i][j-1] + 1, // insertion
 matrix[i-1][j] + 1)); // deletion
 }
 }
 }

 return matrix[b.length][a.length];
}

It works geat and it's fast.
Happy coding!

source: https://gist.github.com/andrei-m/982927

#algorithm

#javascript

#levenshtein