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x_goose_x · Jun 20, 2002, 01:27 PM

You'll need server-side to do this.

whammy · Jun 20, 2002, 02:36 PM

Here's an idea for ya...

Here's something I was playing around with... since I use random randomness, and intersperse a date stamp as well, the odds against ever getting the same number twice are well... a lot higher than I can count!

I'm sure they are astronomical...

Code:

<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 3.2//EN">
<html>
     <head>
<script language="JavaScript" type="text/javascript">
<!--
function UniqueString(){
     var mydate = new Date;
     var myday = mydate.getDate();
     var mymonth = mydate.getMonth()+1;
     var myyear = ((mydate.getYear() < 100) ? "19" : "") + mydate.getYear();
     var myyear = myyear.substring(2,4);
     var myhour = mydate.getHours();
     var myminutes = mydate.getMinutes();
     var myseconds = mydate.getSeconds();
     if(myday < 10) myday = "0" + myday;
     if(mymonth < 10) mymonth = "0" + mymonth;
     if(myhour < 10) myhour = "0" + myhour;
     if(myminutes < 10) myminutes = "0" + myminutes;
     if(myseconds < 10) myseconds = "0" + myseconds;
     var datearray = new Array(mymonth,myday,myyear,myhour,myminutes,myseconds);
     var uniq = "";
     for(i=0;i<datearray.length;i++){
          for(z=0;z<2;z++){
               var which = Math.round(Math.random()*1);
               if(which==0){
                    x = String.fromCharCode(64 + (Math.round(Math.random()*25)+1));
               }
               else{
                    x = String.fromCharCode(47 + (Math.round(Math.random()*9)+1));
               }
               uniq += x;
          }
          uniq += datearray[i];
     }
return uniq;
}
//-->
</script>
          <title>
               Random 24 character string with time factor!
          </title>
     </head>
     <body>
<script language="JavaScript" type="text/javascript">
<!--
     uniq = UniqueString();
     document.write(uniq+"<br />");
// -->
</script>
     </body>
</html>

iamjamtart · Jun 21, 2002, 11:36 AM

Thanks...

I will give this a try...thanks, you're a lifesaver!

litoria · Nov 8, 2007, 02:49 PM

How would i edit this form to generate a shorter unique number. I need a javascript to give a unique number to each person registering on a form of mine. THANKS!

Philip M · Nov 8, 2007, 03:37 PM

It is not possible to generate numbers using JavaScript which are in any way sequential. And the shorter the number the greater the probability that a number will be duplicated.

For example, a number based on hours - minutes - seconds would have 6 digits (e.g. 113542) but the chance of duplication would be quite high.

You really do need a server-side language to do this. I expect you know that JavaScript has no ability to read from or write to a file (except a cookie).

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My form needs a unique number on each load...can it be done?

My form needs a unique number on each load...can it be done?

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