This is documentation for Mathematica 5, which was
based on an earlier version of the Wolfram Language.
View current documentation (Version 11.2)

Documentation / Mathematica / Built-in Functions / Lists and Matrices / List Testing /

Length

FilledSmallSquare Length[expr] gives the number of elements in expr.

FilledSmallSquare See Section 1.4.8, Section 1.8.3 and Section 2.1.5.

FilledSmallSquare When expr is a SparseArray object, Length[expr] returns the length of corresponding ordinary list.

FilledSmallSquare Otherwise, Length[expr] returns 0 whenever AtomQ[expr] is True.

FilledSmallSquare See also: LeafCount, ByteCount, Depth.

FilledSmallSquare New in Version 1; modified in 5.0.

Further Examples