Description
Generates a pseudo-random integer in the range between two specified numbers.
Returns
A pseudo-random integer.
Category
Mathematical functions, Security functions
Function syntax
RandRange(number1, number2[, algorithm])
History
- ColdFusion (2023 release) Update 8 and ColdFusion (2021 release) Update 14: Changed the default algorithm from CFMX_COMPAT to SHA1PRNG.
- ColdFusion MX 7: Added the algorithm parameter.
See also
Parameters
Parameter |
Description |
|---|---|
number1, number2 |
Integer numbers. If the numbers are not in the range -2,147,483,648 - 2,147,483,647, ColdFusion generates an error. |
algorithm |
(Optional) The algorithm to use to generate the random number. ColdFusion installs a cryptography library with the following algorithms:
|
Usage
Very large positive or negative values for the number1 and number2 parameters might result in poor randomness in the results. To prevent this problem, do not specify numbers outside the range -1,000,000,000 - 1,000,000,000. ColdFusion uses the Java Cryptography Extension (JCE) and installs a Sun Java 1.4.2 runtime that includes the Sun JCE default security provider. This provider includes the algorithms listed in the Parameters section (except the default algorithm). The JCE framework includes facilities for using other provider implementations; however, cannot provide technical support for third-party security providers.
Example
The following example generates a random number in the range (-100000,100000) using all three algorithms.
<cfscript>
num1 = -100000;
num2 = 100000;
randAlgorithmArray = ["CFMX_COMPAT", "SHA1PRNG", "IBMSecureRandom"];
for(index = 1; index <= arrayLen(randAlgorithmArray); index++)
{
WriteOutput("The rand number in the range #num1# to #num2# using #randAlgorithmArray[index]# is: "
& randRange(num1, num2, randAlgorithmArray[index]) & "<br/>");
}
</cfscript>
Output
The rand number in the range -100000 to 100000 using CFMX_COMPAT is: 73552
The rand number in the range -100000 to 100000 using SHA1PRNG is: 59144
The rand number in the range -100000 to 100000 using IBMSecureRandom is: 28588