matlab.lang.OnOffSwitchState class

Package: matlab.lang

Represent on and off states with logical values

Description

matlab.lang.OnOffSwitchState is an enumeration class that derives from the logical class. Use this class to specify the data type of properties that accept values of 'on' and 'off' and logical true, false, 1, or 0.

Use this class to constrain property values to any of these values:

Class	Logical True	Logical False
Character vector	'on'	'off'
String scalar	"on"	"off"
Logical	true	false
Logical and numeric	1	0
Enumeration member	matlab.lang.OnOffSwitchState.on	matlab.lang.OnOffSwitchState.off

Because OnOffSwitchState derives from the logical class, you can use these enumeration members in logical expressions.

Enumeration Members

off	Logical false
on	Logical true

Examples

Enable Property Values to Be Logical or on/off

Create a class to represent the state of a computer whose power and monitor can be turned on and off separately. Use OnOffSwitchState to define the class of these properties.

classdef SystemState
   properties
      Power matlab.lang.OnOffSwitchState = 'off'
      Monitor matlab.lang.OnOffSwitchState = 'off'
   end
   methods
      function val = isOn(obj)
         if ~(obj.Power && obj.Monitor)
            val = matlab.lang.OnOffSwitchState.off;
         else
            val = matlab.lang.OnOffSwitchState.on;
         end
      end
   end
end

Create a SystemState object and set the property values to 'on'.

a = SystemState;
a.Power = 'on';
a.Monitor = 'on';

Call the isOn method to determine the state of the system. The method returns a logical value provided by the OnOffSwitchState enumeration.

if isOn(a)
   ...% System is ready to use
end

More About

Specialized Concatenation Behavior

The OnOffSwitchState class enables you to form text expressions by concatenating enumeration members with character vectors or strings. For example, if an object property named Power contains an enumeration member of the OnOffSwitchState class, you can form a character array with a character vector and the property value:

a = SystemState;
a.Power = true;
['The power switch is currently ' a.Power]

ans =

    'The power switch is currently on'

Normally, when forming an array by concatenating character vectors or strings with enumeration members, MATLAB^® attempts to convert the text to the class of the enumeration member. However, the OnOffSwitchState class defines specialized behavior that enables concatenation of enumeration members and text in cases where the text does not correspond to enumeration members defined by the class. In these cases, MATLAB creates an array of the same type as the text.

Here are the rules that MATLAB applies when concatenating character vectors or strings with enumeration members of the OnOffSwitchState class.

• If all array elements are either OnOffSwitchState enumeration members or character vectors, all enumeration members are converted to their char equivalent representation. The resulting array is of type char.

• If all array elements are either OnOffSwitchState enumeration members or strings, all enumeration members are converted to their string equivalent representation. The resulting array is of type string.

• If all array elements are either OnOffSwitchState enumeration members, strings, or character vectors, all enumeration members and character vectors are converted to their string equivalent representation. The resulting array is of type string.

• In all other cases, normal concatenation rules apply. For more information, see Concatenating Objects of Different Classes.

Testing for Equality

The OnOffSwitchState class supports the eq (==) and isequal functions for testing equality between enumeration members and char, string, logical, or numeric types having values of 1 or 0.

Version History

Introduced in R2017a