JavaScript levenshtein
Calculate Levenshtein distance between two strings
1 2 3 4 56 7 8 9 1011 12 13 14 1516 17 18 19 2021 22 23 24 2526 27 28 29 3031 32 33 34 3536 37 38 39 4041 42 43 44 4546 47 48 49 5051 52 53 54 5556 57 58 59 6061 62 63 64 6566 67 68 | function levenshtein (s1, s2) { // Calculate Levenshtein distance between two strings // // version: 909.322 // discuss at: http://phpjs.org/functions/levenshtein // + original by: Carlos R. L. Rodrigues (http://www.jsfromhell.com) // + bugfixed by: Onno Marsman // + revised by: Andrea Giammarchi (http://webreflection.blogspot.com) // + reimplemented by: Brett Zamir (http://brett-zamir.me) // + reimplemented by: Alexander M Beedie // * example 1: levenshtein('Kevin van Zonneveld', 'Kevin van Sommeveld'); // * returns 1: 3 if (s1 == s2) { return 0; } var s1_len = s1.length; var s2_len = s2.length; if (s1_len === 0) { return s2_len; } if (s2_len === 0) { return s1_len; } // BEGIN STATIC var split = false; try{ split=!('0')[0]; } catch (e){ split=true; // Earlier IE may not support access by string index } // END STATIC if (split){ s1 = s1.split(''); s2 = s2.split(''); } var v0 = new Array(s1_len+1); var v1 = new Array(s1_len+1); var s1_idx=0, s2_idx=0, cost=0; for (s1_idx=0; s1_idx<s1_len+1; s1_idx++) { v0[s1_idx] = s1_idx; } var char_s1='', char_s2=''; for (s2_idx=1; s2_idx<=s2_len; s2_idx++) { v1[0] = s2_idx; char_s2 = s2[s2_idx - 1]; for (s1_idx=0; s1_idx<s1_len;s1_idx++) { char_s1 = s1[s1_idx]; cost = (char_s1 == char_s2) ? 0 : 1; var m_min = v0[s1_idx+1] + 1; var b = v1[s1_idx] + 1; var c = v0[s1_idx] + cost; if (b < m_min) { m_min = b; } if (c < m_min) { m_min = c; } v1[s1_idx+1] = m_min; } var v_tmp = v0; v0 = v1; v1 = v_tmp; } return v0[s1_len]; } |
Examples
Running
1 | levenshtein('Kevin van Zonneveld', 'Kevin van Sommeveld'); |
Should return
1 | 3 |
Dependencies
No dependencies, you can use this function standalone.
Open syntax issues
php.js uses JsLint to help us keep our code consistent and prevent some common bugs.
Eventually we want all code to pass or at least take into consideration most fixes suggested by JsLint, following this JsLint configuration we’ve decided on.
Authors
Thanks to the following developers, you get to have levenshtein goodness in JavaScript.

@ Florian: Yeah witnessed on a colleague's PC recently. Should be fixed now!
Kevin van Zonneveld
25 Oct '09