The random operator is used to generate a random value within a specified range or collection. It takes one or two arguments: the first specifies the lower bound or collection, and the second (optional) argument specifies the upper bound. The return value is a randomly selected element from the range or collection.

Int32.Random(Int32 x) returns a random integer [0..x-1].

For example, Int32.Random(100) will return 0, 1, ..., 99—it will never return 100.

The example below shows one way to generate a random string with a random length (between 7 and 11 characters):

let characters = 'ABCDEFGHJKLMNPQRST23456789'.toCharArray in (
  let wordlength = Int32.Random(5)+7 in (
    Sequence{1..wordlength}->collect(a|characters->at(Int32.Random(100).Mod(characters->size)+1))->asSeparatedList( '')
  )
)

Note: The exact algorithm for generating random values may vary depending on the implementation of the operator. Also note that there is no random function on Int64