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length

Length of vector or largest array dimension

Syntax

numberOfElements = length(array)

Description

numberOfElements = length(array) finds the number of elements along the largest dimension of an array. array is an array of any MATLAB® data type and any valid dimensions. numberOfElements is a whole number of the MATLAB double class.

For nonempty arrays, numberOfElements is equivalent to max(size(array)). For empty arrays, numberOfElements is zero.

Examples

Create a 1-by-8 array X and use length to find the number of elements in the second (largest) dimension:

X = [5, 3.4, 72, 28/4, 3.61, 17 94 89];

length(X)
ans =
     8
 

Create a 4-dimensional array Y in which the third dimension is the largest. Use length to find the number of elements in that dimension:

Y = rand(2, 5, 17, 13);

length(Y)
ans =
    17
 

Create a struct array S with character and numeric fields of different lengths. Use the structfun function to apply length to each field of S:

S = struct('f1', 'Name:', 'f2', 'Charlie', ...
           'f3', 'DOB:', 'f4', 1917)
S = 
    f1: 'Name:'
    f2: 'Charlie'
    f3: 'DOB:'
    f4: 1917

structfun(@(field)length(field), S)
ans =
     5
     7
     4
     1

See Also

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