ID - a unique ID/name generator for JavaScript

ID.js

// Generate unique IDs for use as pseudo-private/protected names.
// Similar in concept to
// <http://wiki.ecmascript.org/doku.php?id=strawman:names>.
//
// The goals of this function are twofold:
// 
// * Provide a way to generate a string guaranteed to be unique when compared
//   to other strings generated by this function.
// * Make the string complex enough that it is highly unlikely to be
//   accidentally duplicated by hand (this is key if you're using `ID`
//   as a private/protected name on an object).
//
// Use:
//
//     var privateName = ID();
//     var o = { 'public': 'foo' };
//     o[privateName] = 'bar';
var ID = function () {
  // Math.random should be unique because of its seeding algorithm.
  // Convert it to base 36 (numbers + letters), and grab the first 9 characters
  // after the decimal.
  return (Date.now().toString(36) + Math.random().toString(36).substr(2, 5)).toUpperCase()
  // return '_' + Math.random().toString(36).substr(2, 9);
};

// snippets below extract from http://www.c-sharpcorner.com/blogs/generate-guid-using-javascript1
//http://byronsalau.com/blog/how-to-create-a-guid-uuid-in-javascript/  
  
function createGuid()  
{  
   return 'xxxxxxxx-xxxx-4xxx-yxxx-xxxxxxxxxxxx'.replace(/[xy]/g, function(c) {  
      var r = Math.random()*16|0, v = c === 'x' ? r : (r&0x3|0x8);  
      return v.toString(16);  
   });  
}  
  
var guid = createGuid();  


// http://note19.com/2007/05/27/javascript-guid-generator/  
  
function createGuid() {  
   function s4() {  
      return Math.floor((1 + Math.random()) * 0x10000).toString(16).substring(1);  
   }  
   return s4() + s4() + '-' + s4() + '-' + s4() + '-' + s4() + '-' + s4() + s4() + s4();  
}  
  
var guid = createguid();  

// http://guid.us/GUID/JavaScript  
  
function createGuid(){  
   function S4() {  
      return (((1+Math.random())*0x10000)|0).toString(16).substring(1);  
   }  
   return (S4() + S4() + "-" + S4() + "-4" + S4().substr(0,3) + "-" + S4() + "-" + S4() + S4() + S4()).toLowerCase();  
}  
  
var guid = createGuid();   


// http://slavik.meltser.info/the-efficient-way-to-create-guid-uuid-in-javascript-with-explanation/  
function CreateGuid() {  
   function _p8(s) {  
      var p = (Math.random().toString(16)+"000000000").substr(2,8);  
      return s ? "-" + p.substr(0,4) + "-" + p.substr(4,4) : p ;  
   }  
   return _p8() + _p8(true) + _p8(true) + _p8();  
}  
  
var guid = createGuid();