matlab.metadata.Method Class

Namespace: matlab.metadata
Superclasses: matlab.metadata.MetaData

Describe MATLAB class method

Renamed from meta.method in R2024a

Description

The matlab.metadata.Method class provides information about the methods of MATLAB^® classes. Properties of the matlab.metadata.Method class correspond to method attributes and other information that is specified syntactically in the class definition. All properties are read-only.

The matlab.metadata.Method class is a handle class.

Class Attributes

Abstract	true
ConstructOnLoad	true

For information on class attributes, see Class Attributes.

Creation

You cannot instantiate a matlab.metadata.Method object directly, but there are two ways to obtain an object.

• From the MethodList property of a matlab.metadata.Class object — MethodList contains an array of matlab.metadata.Method objects, one for each class method.

  For example, in this code, replace ClassName with the name of the class whose methods you want to query. mlist(1).Name the name of the first method in the MethodList property.

  mco = ?ClassName;
  mlist = mco.MethodList;
  mlist(1).Name;

• Calling metafunction (since R2026a) — This function returns a matlab.metadata.Method instance for a particular class and method name. Replace ClassName and MethodName with the name of the method you want to query.

  mObj = metafunction("ClassName/MethodName")

Properties

Name — Method name

character vector

Method name, returned as a character vector.

Description — Short description of method

character vector

Short description of the method, returned as a character vector. For user-defined classes, the text for this property comes from code comments in the method definition. If there are no comments, the property returns an empty character vector. For more information on how to include help text for your class methods, see Custom Help Text.

DetailedDescription — Detailed description of method

character vector

Detailed description of the method, returned as a character vector. For user-defined classes, the text for this property comes from code comments in the method definition. If there are no comments, the property returns an empty character vector. For more information on how to include help text for your class methods, see Custom Help Text.

Access — Access level of method

public (default) | protected | private | one or more matlab.metadata.Class objects

The access level of the method, specified as:

• public — unrestricted access

• protected — access from methods in class or subclasses

• private — access by class methods only (not from subclasses)

• List of classes that have access to this method, specified as matlab.metadata.Class objects in the form:

  • A single matlab.metadata.Class object.

  • A cell array of matlab.metadata.Class objects. An empty cell array, {}, is the same as private access.

Static — Value of method attribute Static

false (default) | true

Value of method attribute Static, returned as logical true or false. If true, the method does not depend on an object of the class and does not require an object as input.

For more information, see Static Methods.

Abstract — Value of method attribute Abstract

false (default) | true

Value of method attribute Abstract, returned as logical true or false. If true, the method has no implementation, but the method has a syntax line that can include arguments. For more information, see Abstract Classes and Class Members.

Sealed — Value of method attribute Sealed

false (default) | true

Value of method attribute Hidden, returned as logical true or false. If true, the method cannot be redefined in a subclass. Attempting to define a method with the same name in a subclass causes an error.

Hidden — Value of method attribute Hidden

false (default) | true

Value of method attribute Sealed, returned as logical true or false. When false, the method name appears in the list of methods displayed using the methods or methodsview command. When set to true, the method name is not included in these listings or when displaying the object in the Command Window.

Signature — Information about method input and output arguments

matlab.metadata.CallSignature instance

Since R2026a

Information about the method input and output arguments, specified as a matlab.metadata.CallSignature instance. The CallSignature instance contains information about the arguments and whether or not the method uses arguments blocks.

DefiningClass — Class that defines method

matlab.metadata.Class object

Class that defines the method, returned as a matlab.metadata.Class object representing the defining class. The defining class is always the most specific class from the perspective of the matlab.metadata.Method object. Therefore, if a subclass overrides an inherited method, then the defining class for the subclass matlab.metadata.Method object is the subclass. Similarly, the defining class for the superclass matlab.metadata.Method object is the superclass.

Examples

Use Introspection to Get Information About Methods

Use introspection to get inheritance information about the IntrospectionExample class.

classdef IntrospectionExample
    % IntrospectionExample  Performs basic functions on two numbers
    % Class methods find the sum and product of its properties.
    properties
        % a  First property
        % First of two numeric properties
        a {mustBeNumeric} = 0
        
        % b  Second property
        % Second of two numeric properties
        b {mustBeNumeric} = 0
    end
    
    methods
        function sum = addNumbers(obj)
            % addNumbers  Sum the properties
            %   Finds the sum of properties a and b.
            sum = obj.a + obj.b;
        end
        function prod = multNumbers(obj)
            % multNumbers  Multiply the properties
            %   Finds the product of properties a and b.
            prod = obj.a*obj.b;
        end
    end
end

Create a metaclass instance for IntrospectionExample.

mc = ?IntrospectionExample

mc = 

  Class with properties:

                    Name: 'IntrospectionExample'
             Description: 'Performs basic functions on two numbers'
     DetailedDescription: '  Class methods find the sum and product of its properties.'
                  Hidden: 0
                  Sealed: 0
                Abstract: 0
             Enumeration: 0
         ConstructOnLoad: 0
        HandleCompatible: 0
         InferiorClasses: [0×1 matlab.metadata.Class]
               Namespace: [0×0 matlab.metadata.Namespace]
                 Aliases: [0×1 string]
    RestrictsSubclassing: 0
            PropertyList: [2×1 matlab.metadata.Property]
              MethodList: [4×1 matlab.metadata.Method]
               EventList: [0×1 matlab.metadata.Event]
   EnumerationMemberList: [0×1 matlab.metadata.EnumerationMember]
          SuperclassList: [0×1 matlab.metadata.Class]

Access the first method in the MethodList property of mc to get a matlab.metadata.Method object.

mc.MethodList(1)

ans = 

  Method with properties:

                   Name: 'multNumbers'
            Description: 'Multiply the properties'
    DetailedDescription: '    Finds the product of properties a and b.'
                 Access: 'public'
                 Static: 0
               Abstract: 0
                 Sealed: 0
                 Hidden: 0
              Signature: [1×1 matlab.metadata.CallSignature]
               FullPath: 'C:\Work\IntrospectionExample.m'
          DefiningClass: [1×1 matlab.metadata.Class]

Version History

Introduced in R2008a

R2026a: Signature property replaces InputNames and OutputNames

The Signature property provides more detailed information about method arguments than the existing InputNames and OutputNames properties. The Signature property is an instance of matlab.metadata.CallSignature, which provides not just the names of input and output arguments, but also information about argument validation and default values.

MATLAB will continue to recognize the InputNames and OutputNames properties.

R2026a: Use metafunction to get a matlab.metadata.Method instance

metafunction provides another way to access method metadata. When you call metafunction on a method, the function returns a matlab.metadata.Method instance.

R2024a: Renamed from meta.method

The namespace and class name of meta.method have been changed to matlab.metadata.Method. The behavior remains the same.

MATLAB will continue to recognize the old metaclass names in most contexts. However, code that relies on string comparisons to identify metaclasses might need to be updated to continue to work as expected. For example, if mObj in the example below is a matlab.metadata.Method instance, the code under the case statement for 'meta.method' does not execute because class(mObj) returns 'matlab.metadata.Method'.

switch class(mObj)
   case 'meta.method'
       % code to execute if mObj is a meta.method instance
   ...
end

To ensure this code continues to work as intended, use an if statement with isa. The isa command recognizes both the old and new names of the class.

if isa(mObj,'meta.method') 
       % code to execute if mObj is a matlab.metadata.Method instance
   else
       ...
   end

If compatibility with older releases of MATLAB is not a concern, you can update 'meta.method' to 'matlab.metadata.Method'. However, continue to use the old name if your code needs to run on versions of MATLAB before R2024a.

R2022a: Description and DetailedDescription properties contain text from code comments

For user-defined classes with appropriately placed code comments, the Description and DetailedDescription properties are populated with text pulled from those comments. For more information on how to use code comments to store custom help text for user-defined classes, see Custom Help Text.