Create GUID / UUID in JavaScript? - Stack Overflow

There have been a couple attempts at this. The question is: do you want actual GUIDs, or just random numbers that look like GUIDs? It's easy enough to generate random numbers. From http://note19.com/2007/05/27/javascript-guid-generator/ (after some clean-up for clarity's sake):

var guid = (function() {    function s4() {      return Math.floor((1 + Math.random()) * 0x10000)                 .toString(16)                 .substring(1);    }    return function() {      return s4() + s4() + '-' + s4() + '-' + s4() + '-' +             s4() + '-' + s4() + s4() + s4();    };  })();

However, note in the comments that such values are not genuine GUIDs. There's no way to generate real GUIDs in Javascript, because they depend on properties of the local computer that browsers do not expose. You'll need to use OS-specific services like ActiveX: http://p2p.wrox.com/topicindex/20339.htm Edit: not correct - RFC4122 allows random ("version 4") ids. See other answers for specifics

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