randRange

Generates a random integer between two specified numbers.
Requests for random integers that are greater than 100,000,000
result in non-random numbers, to prevent overflow during
internal computations.

randRange(number1, number2 [, algorithm]) → returns numeric

Argument Reference

number1 numeric
Required

number2 numeric
Required

algorithm string
Default: `CFMX_COMPAT`

CF 7+ The algorithm to use to generated the random number.

Values:

CFMX_COMPAT
SHA1PRNG
IBMSecureRandom
NativePRNG
NativePRNGBlocking
NativePRNGNonBlocking

Links more information about randRange

A better RandRange - RandRange cannot handle large integers and you will encounter bugs when you try to use min or max values that are near the maximum and minimum integer sizes. This shows another way to generate a random int or long.
ACF Bug 4132630 - RandRange issues dealing with large integers - Does not produce random results when range values are very large.
The Right way to use SecureRandom - Good information about choosing a random number algorithm.

Examples
Sample code invoking the randRange function

Tag Example

The following example calls the Randomize function to seed the random number generator and generates 10 random numbers.

<cfset r = randomize(7, "SHA1PRNG")> 
 <cfset local.myInt = 1 /> 
 <cfset local.myInt2 = 999 /> 
<!--- Generate and display the random number. ---> 
 <cfoutput><p><b> 
 RandRange returned: #randRange(local.myInt, local.myInt2, "SHA1PRNG")# 
 </cfoutput></b></p>

Script Example

<cfscript> 
 bytes = []; 
 bytecount = 32; 
 arrayResize( bytes, byteCount ); 
 for (  i = 1 ; i <= byteCount ; i++ ) { 
  bytes[ i ] = randRange( -128, 127, "SHA1PRNG" ); 
         } 
 </cfscript> 
 <cfdump var="#bytes#" />

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randRange

Argument Reference

number1 numeric Required

number2 numeric Required

algorithm string Default: CFMX_COMPAT