/*

 * Natural Sort algorithm for Javascript

 *

 * Author: Brian Huisman

 * Based on: Dave Koelle's work www.davekoelle.com/alphanum.html

 *

 * code source on http://www.davekoelle.com/files/alphanum.js

 *

 */

 var naturalSort = function (a, b) {

  function chunkify(t) {

    var tz = new Array();

    var x = 0, y = -1, n = 0, i, j;

​

    while (i = (j = t.charAt(x++)).charCodeAt(0)) {

      var m = (i == 46 || (i >=48 && i <= 57));

      if (m !== n) {

        tz[++y] = "";

        n = m;

      }

      tz[y] += j;

    }

    return tz;

  }

​

  var aa = chunkify(a.toLowerCase());

  var bb = chunkify(b.toLowerCase());

​

  for (x = 0; aa[x] && bb[x]; x++) {

    if (aa[x] !== bb[x]) {

      var c = Number(aa[x]), d = Number(bb[x]);

      if (c == aa[x] && d == bb[x]) {

        return c - d;

      } else return (aa[x] > bb[x]) ? 1 : -1;

    }

  }

  return aa.length - bb.length;

};

​

/*

 * Sample usages, using javascript's native array's .sort() method

 *

 * see https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Array/sort

 */

var stringArray = [' ciao', 'ciao', 'hello', 'hellothere', 'hello there'];

/* non-ASCII characters, i.e. strings with accented characters (e, é, è, a, ä, etc.),  */

var stringArrayWithNonAsciiChars = ['réservé', 'réserve', 'premier', 'cliché', 'communiqué', 'café', 'adieu'];

​

var numericStringArray = ['80', '9', '700'];

var stringAlphanumericalOne = [' ','1','a'];

var stringAlphanumericalTwo = ['img ','img1','imga', 'imgz'];

var stringAlphanumericalThree = ['img 99','img199','imga99', 'imgz99'];

var stringAlphanumericalFour = ['img12.png','img10.png','img2.png','img1.png']; 

​

console.log( stringArray.sort(naturalSort) );

console.log( stringArrayWithNonAsciiChars.sort(naturalSort) );

console.log( numericStringArray.sort(naturalSort) );

console.log( stringAlphanumericalOne.sort(naturalSort) );

/* in the call below it fails! order should be ["img ", "img1", "imga", "imgz"] */

console.log( stringAlphanumericalTwo.sort(naturalSort) );

/* in the call below it fails! order should be ["img 99", "img199", "imga99", "imgz99"] */

console.log( stringAlphanumericalThree.sort(naturalSort) );

​