isa

Determine if input is instance of specified class

Syntax

tf = isa(A,classname)

tf = isa(A,numericCategory)

Description

tf = isa(A,classname) returns 1 (true) if A is an instance of classname or a subclass of classname. Otherwise, it returns 0 (false). The input argument A can have any data type.

If A is an object, then isa returns 1 if dataType is either the class of A or a superclass of A.

tf = isa(A,numericCategory) returns 1 (true) if the data type of A belongs to the category specified by numericCategory. Otherwise, it returns 0 (false).

If A is an object, then isa returns 1 if the class of A, or any superclass of A, belongs to the specified category.

Examples

Determine If Variables Have Specified Data Types

Create a numeric variable and determine if its data type is double.

A = 3.1416;
tf = isa(A,'double')

tf = logical
   1

Create an array of 32-bit integers and determine if its data type is int32.

A = int32([0 2 4 6 8])

A = 1×5 int32 row vector

   0   2   4   6   8

tf = isa(A,'int32')

tf = logical
   1

Determine if the data type of A is char.

tf = isa(A,'char')

tf = logical
   0

Determine If Variable Type Belongs to Specified Categories

Create an array whose data type is uint8. Determine if the array has a data type that belongs to the integer category.

A = uint8([0 2 4 6 8])

A = 1×5 uint8 row vector

   0   2   4   6   8

tf = isa(A,'integer')

tf = logical
   1

Determine if the data type of A belongs to the float category.

tf = isa(A,'float')

tf = logical
   0

Input Arguments

A — Input array

array

Input array.

classname — Class name

character vector | string scalar

Class name, specified as a character vector or string scalar. classname can be the name of:

• Any fundamental data type or MATLAB^® class

• A Java^® or .NET class

The table shows the names of many commonly used MATLAB data types.

'half'	Half-precision number
'single'	Single-precision number
'double'	Double-precision number
'int8'	Signed 8-bit integer
'int16'	Signed 16-bit integer
'int32'	Signed 32-bit integer
'int64'	Signed 64-bit integer
'uint8'	Unsigned 8-bit integer
'uint16'	Unsigned 16-bit integer
'uint32'	Unsigned 32-bit integer
'uint64'	Unsigned 64-bit integer
'logical'	Logical 1 (true) or 0 (false)
'char'	Character
'string'	String array
'struct'	Structure array
'cell'	Cell array
'table'	Table
'timetable'	Timetable
'function_handle'	Function handle

numericCategory — Data type category

'numeric' | 'float' | 'integer'

Data type category, specified as 'numeric', 'float', or 'integer'. These values represent categories of numeric types, as shown in the table.

'numeric'	Integer or floating-point array, having one of these data types: double single half int8 int16 int32 int64 uint8 uint16 uint32 uint64
'float'	Single- or double-precision floating-point array, having either of these data types: double single half
'integer'	Signed or unsigned integer array, having one of these data types: int8 int16 int32 int64 uint8 uint16 uint32 uint64

Tips

• To test whether the input array is sparse, use the issparse function.

• To test whether the input array has any imaginary or complex elements, use ~isreal(A).

Extended Capabilities

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

Thread-Based Environment

Run code in the background using MATLAB® backgroundPool or accelerate code with Parallel Computing Toolbox™ ThreadPool.

This function fully supports thread-based environments. For more information, see Run MATLAB Functions in Thread-Based Environment.

Version History

Introduced before R2006a