catalogue

Class component

Class building block

Class definition code block

Attribute code block

Method code block

Event code block

Complete class

Enumeration class

Class component

Class building block

        MATLAB ® Organize the class definition code into modular code blocks separated by keywords. All keywords have associated end statements:

• classdef...end - definition of all class components

• properties...end - attribute name declaration, attribute property setting, default value assignment

• methods...end - declaration of method signature, method properties, and function code

• events...end - declaration of event name and attribute

• enumeration...end - declaration of enumeration members and enumeration values of the enumeration class.

properties, methods, events, and enumeration are just keywords in the classdef code block.

Class definition code block

The classdef code block contains the class definitions in the file, starting with the classdef keyword and ending with the end keyword.

classdef (ClassAttributes) ClassName < SuperClass
   ...
end

For example, the following classdef defines a class named MyClass, which is a subclass of the handle class, but it cannot be used to derive subclasses:

classdef (Sealed) MyClass < handle
   ...
end

Attribute code block

The properties code block (one for each unique property set) contains property definitions, including optional initial values. The attribute code block starts with the properties keyword and ends with the end keyword.

classdef ClassName
   properties (PropertyAttributes)
      ...
   end
   ...
end

For example, the following class defines an attribute named Prop1, which has private access rights, and the default value is equal to the output of the date function.

classdef MyClass
   properties (SetAccess = private)
      Prop1 = date
   end
   ...
end

Method code block

The methods code block (one for each unique attribute set) contains the function definition of the class method. The method code block starts with the methods keyword and ends with the end keyword.

classdef ClassName
   methods (MethodAttributes)
      ...
   end
   ...
end

For example:

classdef MyClass
   methods (Access = private)
      function obj = myMethod(obj)
      ...
      end
   end
end

Event code block

The events code block (one for each unique attribute set) contains the name of the event declared by this class. The event code block starts with the events keyword and ends with the end keyword.

classdef ClassName
   events (EventAttributes)
      EventName
   end
   ...
end

For example, the following class defines an event named StateChange, and ListenAccess is set to protected:

classdef EventSource
   events (ListenAccess = protected)
      StateChanged
   end
   ...
end

Complete class

The complete class definition contains any combination of attributes, methods, and event code blocks.

classdef (Sealed) MyClass < handle
   properties (SetAccess = private)
      Prop1 = datenum(date)
   end
   properties
      Prop2
   end
   methods
      function obj = MyClass(x)
         obj.Prop2 = x;
      end
   end
   methods (Access = {?MyOtherClass})
      function d = myMethod(obj)
         d = obj.Prop1 + x;
      end
   end
   events (ListenAccess = protected)
      StateChanged
   end
end

Enumeration class

An enumeration class is a specialized class that defines a fixed set of names that represent a single type value. The enumeration class uses the enumeration code block to contain the enumeration members defined by the class.

The enumeration code block starts with the # enumeration # keyword and ends with the # end # keyword.

classdef ClassName < SuperClass
   enumeration
      EnumerationMember
   end
   ...
end

For example, the following class defines two enumeration members, representing the logical values false and true respectively:

classdef Boolean < logical
   enumeration
      No  (0)
      Yes (1)
   end
end