This is documentation for Mathematica 6, which was
based on an earlier version of the Wolfram Language.
View current documentation (Version 11.2)


evaluates expr with all pseudorandom generators localized, so that uses of SeedRandom, RandomInteger and related functions within the evaluation of expr do not affect subsequent pseudorandom sequences.
  • BlockRandom[expr] in effect saves the states of all pseudorandom generators before evaluating expr, then restores them afterwards.
  • BlockRandom[expr] always gives the same result as just evaluating expr, though it can affect values obtained for subsequent expressions.
  • Many built-in functions in Mathematica effectively use BlockRandom.
New in 6