JavaScript String compare

str_cmpr.js

/**
* Compare a string (a la c) with other and return -1 if smaller, 0 if equals or 1 if higher
* @author: Jan Cássio | hey@jancassio.com
* @usage
* "cupcake".compare("chocolate"); // returns 1;
* "sounds good".compare("sounds good"); // return 0;
* "10.1".compare("10.105"); // returns -1;
*/
String.prototype.compare = function(other)
{
  if( typeof other !== "string" ) return null;
  return (other > this ) ? -1 : Number( other < this );
}