leven

Measure the difference between two strings using the Levenshtein distance algorithm

Install

npm install leven

Usage

import leven from 'leven';

leven('cat', 'cow');
//=> 2

API

leven(first, second, options?)

first

Type: string

First string.

second

Type: string

Second string.

options

Type: object

maxDistance

Type: number

Maximum distance to calculate.

If the actual distance exceeds this value, the function will return maxDistance instead of the actual distance. This can significantly improve performance when you only care about matches within a certain threshold.

Negative and non-integer values are ignored, and the distance is then not capped.

[!TIP] Without maxDistance, the time grows with the product of the string lengths, so two long strings can block for seconds. With it, the time grows only with the string length times maxDistance. Set it for untrusted input.

import leven from 'leven';

leven('abcdef', '123456', {maxDistance: 3});
//=> 3

leven('cat', 'cow', {maxDistance: 5});
//=> 2

closestMatch(target, candidates, options?)

Find the closest matching string from an array of candidates.

target

Type: string

The string to find matches for.

candidates

Type: string[]

Array of candidate strings to search through.

options

Type: object

Same options as leven().

maxDistance

Type: number

Maximum distance to consider. Candidates with a distance greater than this value will be ignored.

Returns the closest matching string from candidates, or undefined if no candidates are provided or if no match is found within maxDistance.

import {closestMatch} from 'leven';

closestMatch('kitten', ['sitting', 'kitchen', 'mittens']);
//=> 'kitchen'

closestMatch('hello', ['jello', 'yellow', 'bellow'], {maxDistance: 2});
//=> 'jello'

// No match within distance threshold
closestMatch('abcdef', ['123456', '1234567890'], {maxDistance: 2});
//=> undefined

Related

• leven-cli - CLI for this module