Length of largest array dimension



L = length(X) returns the length of the largest array dimension in X. For vectors, the length is simply the number of elements. For arrays with more dimensions, the length is max(size(X)). The length of an empty array is zero.


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Find the length of a uniformly spaced vector in the interval [5,10].

v = 5:10
v = 1×6

     5     6     7     8     9    10

L = length(v)
L = 6

Find the length of a 3-by-7 matrix of zeros.

X = zeros(3,7);
L = length(X)
L = 7

Create a string array and compute its length, which is the number of elements in each row.

X = ["a" "b" "c"; "d" "e" "f"]
X = 2x3 string
    "a"    "b"    "c"
    "d"    "e"    "f"

L = length(X)
L = 3

Create a structure with fields for Day and Month. Use the structfun function to apply length to each field.

S = struct('Day',[1 13 14 26],'Month',{{'Jan','Feb', 'Mar'}})
S = struct with fields:
      Day: [1 13 14 26]
    Month: {'Jan'  'Feb'  'Mar'}

L = structfun(@(field) length(field),S)
L = 2×1


Input Arguments

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Input array, specified as a scalar, vector, matrix, or multidimensional array.

Complex Number Support: Yes


  • To find the number of characters in a string or character vector, use the strlength function.

  • length does not operate on tables. To examine the dimensions of a table, use the height, width, or size functions.

Extended Capabilities

C/C++ Code Generation
Generate C and C++ code using MATLAB® Coder™.

GPU Code Generation
Generate CUDA® code for NVIDIA® GPUs using GPU Coder™.

HDL Code Generation
Generate Verilog and VHDL code for FPGA and ASIC designs using HDL Coder™.

See Also

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Introduced before R2006a