JavaScript truncate variable value and save to localStorage

Hello,

We currently have a function that generates a unique ID (see below). I was wondering how we could update the function to take the last 20 digits of the unique id and push it into localStorage for the session. The function also needs to overwrite the unique id stored in localStorage if the function is execuited a 2nd or more times within the same session.

var _unqid = '' + Math.abs((function(s){return s.split("").reduce(function(a,b){a=((a<<5)-a)+b.charCodeAt(0);return a&a},0);})(navigator.userAgent)) + "" + new Date().getTime() + "" + Math.floor(Math.random() * 1000);
var x =_unqid;

Thanks
PlumInternetAsked:
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Rainer JeschorCommented:
Hi,
perhaps the following helps:
var _unqid = '' + Math.abs((function(s){return s.split("").reduce(function(a,b){a=((a<<5)-a)+b.charCodeAt(0);return a&a},0);})(navigator.userAgent)) + "" + new Date().getTime() + "" + Math.floor(Math.random() * 1000);
var x =_unqid.slice(-20);
localStorage.setItem("uniqueIdShort", x);

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HTH
Rainer
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PlumInternetAuthor Commented:
Perfect, worked like a charm thanks for your help.
0
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