Simple english language ordinal for an integer e.g. 1st, 2nd, 12th, 25th - 'map-reduce logic'

_strord.js

// author: lo sauer 2011 - lsauer.com; see also 'furls' concise version: https://gist.github.com/986113 
// description: solution with a 'map-reduce' mindset
// note: JS converts string-numbers on the fly e.g. "7"&3 >3; this comes in handy
//       A similar and more concise solutions could be implemented:
//       a=(a+'').substr(-2);
// included in https://github.com/lsauer/is-library 

function (a){a=(a|0+'').split('').slice(-2).reduce(function(a,b){return 1==a?0:(b>3 ? 0 : b); });return ['th','st','nd','rd'][a]; };


// Annotated & expanded
// Note: for 'teens case' (e.g. 12th) we cannot apply a straightforwards bit cutoff-range such as &range|start as the ORed 'start' mask would be 0 or 1
var strord = function (a,i18n){
	//summary: cast to string, map (e.g. atomize) and reduce
	a=(a|0+'')							//cast to string
	.split('')							//atomize
	.slice(-2)							//get the last two elements
	.reduce( 							//reduce arithmetically to a single value
		function(a,b){
			if(1==a) return 0;			//teens case -> return 0 (#el containing 'th') 
			else return b>3 ? 0 : b;	//if b>3 return 0 -> 'th'
		}
	);
	var oi18n = {'en': ['th','st','nd','rd']}
	i18n=i18n||'en';
	return oi18n[i18n][a];	//map number to a string
};
ord(112)
>"th"

ord(3022)
>"nd"

//Here is a regex based, albeit slower version by  tsaniel (github)
function(a){return[,"st","nd","rd"][/1?.$/.exec(a)]||"th"}

License

Dual licensed: BSD or Your Driver's License

1.<INSERT YOUR DRIVER'S LICENSE + MUGSHOT HERE>

2.<BSD LICENSE>
Copyright (c) 2011 lo sauer.
All rights reserved.

Redistribution and use in source and binary forms are permitted
provided that the above copyright notice and this paragraph are
duplicated in all such forms and that any documentation,
advertising materials, and other materials related to such
distribution and use acknowledge that the software was developed
by the <organization>.  The name of the
University may not be used to endorse or promote products derived
from this software without specific prior written permission.
THIS SOFTWARE IS PROVIDED ``AS IS'' AND WITHOUT ANY EXPRESS OR
IMPLIED WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED
WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE.

minified.js

function (a){a=(a|0+'').split('').slice(-2).reduce(function(a,b){return 1==a?0:(b>3 ? 0 : b);});return ['th','st','nd','rd'][a];};

package.json

{
  "name": "strordinal",
  "description": "Return the ordinal suffix for a number. In case of a float the number is floored.",
  "keywords": ["ordinal","i18n","suffix","conversion","th","st","nd","rd" ]
}