New (RandomNumberGenerator constructor)

Create a random number object

New is a member of the RandomNumberGenerator class.

The New method creates a random number. The kind of random number depends on the parameters specified when New is invoked:

• If no parameters are specified, New returns an unpredictable random number each time it is called.
• If a Salt parameter is specified, New returns an unpredictable random number that is based on initial input that has an extra degree of randomness.
• If only a Seed parameter is specified, New returns the next number in a specific series of pseudo-random numbers. Subsequent identical calls produce the next items in the series; recreating or resetting the object with the same seed lets you reproduce the series.

Syntax

  %rand = new([Seed=seed] [, Salt=salt])

Syntax terms

%rand

A RandomNumberGenerator object variable.

Seed=seed

An optional, name required, argument that lets you specify a “seed” for the random number generator. If you provide no seed, the method generates a new, “random,” starting value for the random number generator, which produces an unpredictable random number result. seed is a string or a longstring.

Salt=salt

An optional, name required, argument that lets you specify a “salt” for the random number generator. A salt is additional data to be used (along with the explicit or default seed) to improve the randomness of the random generator's initial value. salt is a string or a longstring.

Usage Notes

• If no Seed argument is specified, the New method generates a random seed (based on multiple, internal system data like STCK value, frequently-changed parts of memory, and so on).
• If you want to increase the randomness of the initial value passed to the random number generator, but you don't want a reproducible sequence, you can pass additional data to be used to generate the random starting value, maybe from something a user types in. This additional value is called a salt.
• Since the likely use of explicitly specifying a seed is to produce a reproducible random sequence, there is probably not much reason to specify both a salt and a seed, which would nullify reproducibility.
• For an example of the New method, see the RandomNumberGenerator class page.