This is documentation for Mathematica 8, which was
based on an earlier version of the Wolfram Language.
View current documentation (Version 11.2)


splits list into sublists consisting of runs of identical elements.
treats pairs of adjacent elements as identical whenever applying the function test to them yields True.
  • The default function used to test whether elements are identical is SameQ.
  • Split can be used to perform run-length encoding. »
Split in increasing runs of elements:
Decreasing runs of elements:
Split based on first elements:
Split at jumps:
Split so that in each sublist successive elements are not the same:
Split after every occurrence of :
Split before every occurrence of :
Group together identical elements:
Run-length encoding:
Group equivalence classes according to an equivalence function:
Distribution of lengths of runs of 0s or 1s in the first million bits of :
Distribution of lengths of runs of 0s or 1s in one million pseudorandom bits:
Flatten acts an inverse of Split:
Find runs of numbers in base 10 that contain the same number of 1s:
Iterated run-length encoding :
New in 3