Generate GUID using JavaScript

I had a requirement to generate the GUID type id using JavaScript. I started worked on that, in the mean while I came across some sites and they already given some snippets to generate the guid.

 

Here, I will give those compilations of those snippets.

 

Generate random unique id / guid using Math.Random

Example 1: 

// 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();

Example 2:

// 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();

Example 3: 

// 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();

Generate GUID using the Regular Expression

 

Example 4: 

//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();