natural-compare

@version 1.4.0 @date 2015-10-26 @stability 3 - Stable

Natural Compare –

Compare strings containing a mix of letters and numbers in the way a human being would in sort order. This is described as a "natural ordering".

Standard sorting: Natural order sorting: img1.png img1.png img10.png img2.png img12.png img10.png img2.png img12.png

String.naturalCompare returns a number indicating whether a reference string comes before or after or is the same as the given string in sort order. Use it with builtin sort() function.

Installation

• In browser

<script src=min.natural-compare.js></script>

• In node.js: npm install natural-compare-lite

require("natural-compare-lite")

Usage

// Simple case sensitive example var a = ["z1.doc", "z10.doc", "z17.doc", "z2.doc", "z23.doc", "z3.doc"]; a.sort(String.naturalCompare); // ["z1.doc", "z2.doc", "z3.doc", "z10.doc", "z17.doc", "z23.doc"] // Use wrapper function for case insensitivity a.sort(function(a, b){ return String.naturalCompare(a.toLowerCase(), b.toLowerCase()); }) // In most cases we want to sort an array of objects var a = [ {"street":"350 5th Ave", "room":"A-1021"} , {"street":"350 5th Ave", "room":"A-21046-b"} ]; // sort by street, then by room a.sort(function(a, b){ return String.naturalCompare(a.street, b.street) || String.naturalCompare(a.room, b.room); }) // When text transformation is needed (eg toLowerCase()), // it is best for performance to keep // transformed key in that object. // There are no need to do text transformation // on each comparision when sorting. var a = [ {"make":"Audi", "model":"A6"} , {"make":"Kia", "model":"Rio"} ]; // sort by make, then by model a.map(function(car){ car.sort_key = (car.make + " " + car.model).toLowerCase(); }) a.sort(function(a, b){ return String.naturalCompare(a.sort_key, b.sort_key); })

• Works well with dates in ISO format eg "Rev 2012-07-26.doc".

Custom alphabet

It is possible to configure a custom alphabet to achieve a desired order.

// Estonian alphabet String.alphabet = "ABDEFGHIJKLMNOPRSŠZŽTUVÕÄÖÜXYabdefghijklmnoprsšzžtuvõäöüxy" ["t", "z", "x", "õ"].sort(String.naturalCompare) // ["z", "t", "õ", "x"] // Russian alphabet String.alphabet = "АБВГДЕЁЖЗИЙКЛМНОПРСТУФХЦЧШЩЪЫЬЭЮЯабвгдеёжзийклмнопрстуфхцчшщъыьэюя" ["Ё", "А", "Б"].sort(String.naturalCompare) // ["А", "Б", "Ё"]

External links

• [GitHub repo][https://github.com/litejs/natural-compare-lite]
• jsperf test

Licence

Copyright (c) 2012-2015 Lauri Rooden <lauri@rooden.ee>
The MIT License