Subclass Syntax - MATLAB & Simulink (original) (raw)
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Subclass Definition Syntax
To define a class that is a subclass of another class, add the superclass to the classdef line after a < character:
classdef ClassName < SuperClass
When inheriting from multiple classes, use the & character to indicate the combination of the superclasses:
classdef ClassName < SuperClass1 & SuperClass2
See Class Member Compatibility for more information on deriving from multiple superclasses.
Class Attributes
Subclasses do not inherit superclass attributes.
Subclass double
Suppose you want to define a class that derives from double and restricts values to be positive numbers. The PositiveDouble class:
- Supports a default constructor (no input arguments). See No Input Argument Constructor Requirement
- Restricts the inputs to positive values using mustBePositive
- Calls the superclass constructor with the input value to create the double numeric value
classdef PositiveDouble < double methods function obj = PositiveDouble(data) if nargin == 0 data = 1; else mustBePositive(data) end obj = obj@double(data); end end end
Create an object of the PositiveDouble class using a 1-by-5 array of numbers:
You can perform operations on objects of this class like any double.
Objects of the PositiveDouble class must be positive values.
Error using mustBePositive (line 19) Value must be positive.
Error in PositiveDouble (line 7) mustBePositive(data)