classdef()

Object-Oriented Programming

classdef() is a MATLAB®-compatible object-oriented programming function for define a class with properties and instance methods. instances are created with classname(args) and methods are called as obj.methodname(args). the first method parameter receives the instance. Run it online in your browser with SimLab — free, no install, no license required.

Define a class with properties and instance methods. Instances are created with ClassName(args) and methods are called as obj.methodName(args). The first method parameter receives the instance.

▶ Try classdef() in SimLab — Free

Syntax

classdef ClassName

  properties

    propName = defaultValue

end

  methods

    function obj = ClassName(args)

      % constructor body

end

    function out = methodName(obj, args)

      % method body

end

end

end

classdef ChildClass < ParentClass  % single inheritance

methods (Static)
  function r = name(args)
    ...
  end
end  % Static method

properties (Constant)
  NAME = value
end  % Class-level constant

Examples — run classdef() in your browser

classdef Point
  properties
    x = 0
    y = 0
  end
  methods
    function obj = Point(xv, yv)
      obj.x = xv; obj.y = yv;
    end
    function d = norm(obj)
      d = sqrt(obj.x^2 + obj.y^2);
    end
  end
end
p = Point(3, 4);
d = p.norm();

▶ Run

classdef Vec
  properties
    v = [0;0]
  end
  methods
    function obj = Vec(arr)
      obj.v = arr;
    end
    function r = plus(a, b)
      r = Vec(a.v + b.v);
    end
  end
end
c = Vec([1;2]) + Vec([3;4]);  % [4;6] via overloaded +

▶ Run

Limitations

Single inheritance only. Operator overloading via plus, minus, mtimes, mrdivide, mpower, eq, ne, lt, gt, uminus. Static methods (methods (Static)) and Constant properties (properties (Constant)) accessible as ClassName.fn() / ClassName.NAME without instantiation. Not supported: events, enumeration, Abstract, Sealed, handle classes, multiple inheritance, Access=private enforcement, Constants referencing other class Constants, Static/Constant inheritance through superclass.

Frequently Asked Questions about classdef()

Is the classdef() function free to use in SimLab?

The browser workspace requires no MATLAB® license or installation. Connected features require network access and may have account, tier, availability, or usage limits. You can open classdef() and 510+ other MATLAB®-compatible function references at simulations4all.com/simlab.

Do I need to install MATLAB to use classdef()?

No. SimLab’s core parser, workspace state, and most functions run locally in your browser. The classdef() function requires no MATLAB® license or desktop software download.

What does classdef() do?

Define a class with properties and instance methods. Instances are created with ClassName(args) and methods are called as obj.methodName(args). The first method parameter receives the instance. It is a MATLAB®-compatible object-oriented programming function available in SimLab with the same calling syntax as MATLAB® — typically: classdef ClassName.

Can I run classdef() in my browser?

Yes. Open SimLab at simulations4all.com/simlab, write or paste code that calls classdef(), and run it. This function’s calculation runs locally in the browser. SimLab session analytics, sharing, feedback, and eligible acceleration have separate network boundaries.

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