length

Length of the longest dimension.

Syntax

n = length(X)

Description

Returns the largest dimension size of X. For a vector, this is the number of elements. For a matrix, it’s max(size(X)). For an empty array, returns 0.

For most array-shape questions, numel (total element count) or size (per-dimension) is more appropriate; length is most useful for vectors.

Examples

length([10 20 30 40])  % 4
length(zeros(3,5))     % 5
length([])             % 0

See also

• size — Sizes along all dimensions, or along one specific dimension.
• numel — Total number of elements.
• ndims — Number of dimensions of the input.
• isempty — Test whether the input has zero elements.