damm

Damm check digit algorithm

damm

A JavaScript implementation of the Damm algorithm, a check digit algorithm created by H. Michael Damm. It detects all single-digit errors and adjacent transposition errors (swapping adjacent numbers). For more information see the Wikipedia article which includes a description of the algorithm and links to the relevant papers.

npm install damm
var damm = require('damm');
 
damm.generate('572'); // '4' 
 
damm.append('572'); // '5724' 
 
damm.verify('5724'); // true 
 
// Single-digit error 
damm.verify('5734'); // false 
 
// Adjacent transposition error 
damm.verify('5274'); // false