The Random(len, alphabet) calling sequence generates a random string of a given length, with the option of restricting the characters that form the returned string.

The Random(len) calling sequence returns a string of length len whose characters are randomly distributed and in the numeric range . That is, any non-zero 8-bit character can appear, and all appear with equal likelihood.

If the second optional argument, alphabet, is included in the calling sequence, it specifies the "alphabet" upon which the random string is generated. This option can assume one of two forms. If it is of type string, then the characters in that string are taken to be the alphabet from which to randomly draw characters in the output string. The alphabet characters must appear in US-ASCII order and cannot contain repetitions.

If the alphabet parameter is a symbol, then it must be one of the following recognized character class names.

Because the random number generator used by Random is independent of the random number generator rand, the randomize command cannot be used to seed the former.  Therefore, the StringTools package provides the Randomize command that can be used to seed the random number generator Random used by the StringTools package.

The Randomize command takes a positive integer argument seed as its sole argument. This number is used to seed the random number generator. The seed argument is optional, however, and a value derived from the system clock will be used to seed the random number generator if the seed argument is omitted.