
Contents > CFML Reference > ColdFusion Functions > Randomize

Randomize

Seeds the ColdFusion random number generator with an integer number. Seeding the generator helps ensure that the Rand function generates highly random numbers.

A non-random decimal number, in the range 0 - 1.

Mathematical functions

Randomize(number)

Rand, RandRange

Parameter	Description
number	A number

Call this function before calling Rand. Although this function returns a decimal number, it is not a random number.

<h3>Randomize Example</h3>
<p>Call Randomize to seed the random number generator. This helps 
to ensure the randomness of numbers generated by Rand.
<cfif IsDefined("FORM.myRandomInt")>
   <cfif IsNumeric(FORM.myRandomInt)>
     <cfoutput><p><b>Seed value is #FORM.myRandomInt#</b>
      </cfoutput><br>
    <cfset r = Randomize(FORM.myRandomInt)>
     <cfloop index = "i" from = "1" to = "10" step = "1">
        <cfoutput>Next random number is #Rand()#</cfoutput><br>
     </cfloop><br>
   <cfelse>
      <p>Please enter a number.
   </cfif>
</cfif>
<form action = "randomize.cfm">
<p>Enter a number to seed the randomizer:
<input type = "Text" name = "MyRandomInt">
<p><input type = "Submit" name = "">
</form>


Contents > CFML Reference > ColdFusion Functions > Randomize

Version 6.1

Comments are no longer accepted for ColdFusion MX 6.1. ColdFusion 8 is the current version.

Comments

No screen name said on Nov 27, 2003 at 2:36 AM :

This function does no longer work with GetTickCount() as a parameter since it does only take integers as parameter. In CF 5 samples GetTickCount was often used to initialize the randomize function.

Terry Luedtke said on Sep 21, 2004 at 2:58 PM :

You could try something like randomize(right(getTickCount(), 9)).

bizarrojack said on Jan 6, 2005 at 9:12 AM :

Getting a truly random number isn't easy. This macromedia blog entry should be of use to anyone who is using rand.

http://www.markme.com/cantrell/archives/004256.cfm
Thank you Christian Cantrell!

Since I am java-phobic, though, if anyone knows how to seed the PRNG with something from PRNGD or EGD or a /dev/random, I'd love to see that.

RSS feed | Send me an e-mail when comments are added to this page | Comment Report

Current page: http://livedocs.adobe.com/coldfusion/6.1/htmldocs/functa61.htm