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Determine whether input is integer array



TF = isinteger(A) returns logical 1 (true) if A is an array of integer type. Otherwise, it returns logical 0 (false).

Integer types in MATLAB® include: int8, int16, int32, int64, uint8, uint16, uint32, and uint64. For more information, see Integer Classes.


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Determine if a real number is an integer type.

TF = isinteger(2)
TF = logical

MATLAB® stores a real number as a double type by default.

Convert the number to a signed 8-bit integer type using the int8 function. Check if it is an integer type.

TF = isinteger(int8(2))
TF = logical

Determine if a complex number is an integer type.

A = 3.5 - 2.5i
A = 3.5000 - 2.5000i
TF = isinteger(A)
TF = logical

MATLAB stores a complex number as a double type by default.

Convert the complex number into a signed 32-bit integer type using the int32 function. Check if it is an integer type.

B = int32(A)
B = int32
    4 -    3i
TF = isinteger(B)
TF = logical

When a number with decimal digits is converted to an integer type, MATLAB rounds it to the nearest integer.

Determine if an array containing integer numbers is an integer type.

Create an array using the int8 function. Check if it is an integer type.

A = [int8(1:5)]
A = 1x5 int8 row vector

   1   2   3   4   5

TF = isinteger(A)
TF = logical

Now, create a cell array that contains the array A and other integer numbers. Use class to identify the type of the cell array. Check if it is an integer type.

B = {A int8(-4); int8(2) int8(1)}
B=2×2 cell array
    {[1 2 3 4 5]}    {[-4]}
    {[        2]}    {[ 1]}

type = class(B)
type = 
TF = isinteger(B)
TF = logical

The cell array is not an integer type since it is a cell type.

Input Arguments

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Input array, specified as a scalar, vector, matrix, or multidimensional array. MATLAB has the following integer types.

Integer TypeDescription


8-bit signed integer


16-bit signed integer


64-bit signed integer


32-bit signed integer


8-bit unsigned integer


16-bit unsigned integer


32-bit unsigned integer


64-bit unsigned integer


  • For a floating-point number of a single or double type, you can check if it is also an integer by using the round function (within the floating-point relative accuracy eps). If the rounded value of the number is equal to the original value before rounding, then the number is an integer. For example, 2 == round(2) returns logical 1 (true) since 2 is an integer.

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™.

Version History

Introduced before R2006a