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Jaro-Winkler

A string similarity function using the Jaro-Winkler distance metric. Returns a number between 0 and 1. A 0 being no similarity and a 1 being an exact match.

Read more about it on Wikipedia.

Install

Install in your Node project using npm as usual; npm install jaro-winkler. It also works in the browser, just include the source within index.js in your project however you prefer. Note that the distance function will be added to the global scope if it's not included with a tool like Browserify.

Example Usage

var distance = require('jaro-winkler');

distance('MARTHA', 'MARHTA');
// 0.961

distance('DWAYNE', 'DUANE');
// 0.84

distance('DIXON', 'DICKSONX');
// 0.814


// Case Insensitive

distance('MARTHA', 'MARTHA');
// 1

distance('mArThA', 'MaRtHa', { caseSensitive: false });
// 1

Sample App

Here's contrived sample of how you might utilize a distance metric in your own app. This shows how you might offer a helpful message when a user fat-fingers a command.

#!/usr/bin/env node

'use strict';

var distance = require('jaro-winkler');
var commands = ['open', 'close', 'save', 'revert', 'select', 'copy', 'duplicate', 'add', 'subtract'];
var rated    = [];
var args     = process.argv.slice(2);

commands.forEach(function(command) {
  rated.push({
    command: command,
    distance: distance(args[0], command)
  });
});

rated.sort(function(a, b) {
  if (a.distance < b.distance) {
    return 1;
  } else if (a.distance > b.distance) {
      return -1;
  } else {
    return 0;
  }
});

if (rated[0].distance === 1) {
  console.log("Running " + rated[0].command + "!");
} else {
  console.log("Did you mean " + rated[0].command + "?");
}

process.exit(0);