MATLAB Object-Oriented Programming

However, the line object referred to by a.Prop has not been copied. The handle

contained in a.Prop refers to the same object as the handle contained in b.Prop.

a.Prop == b.Prop

ans =

logical

1

For more detailed information on the behavior of the copy operation, see

matlab.mixin.Copyable.copy.

Customize Copy Operation

Customize handle object copy behavior by deriving your class from

matlab.mixin.Copyable. The matlab.mixin.Copyable class is an abstract base

class that derives from the handle class. matlab.mixin.Copyable provides a template

for customizing object copy operations by defining:

• matlab.mixin.Copyable.copy — Sealed method that defines the interface for
  copying objects


• matlab.mixin.Copyable.copyElement — Protected method that subclasses can
  override to customize object copy operations for the subclass

The matlab.mixin.Copyable copy method, calls the copyElement method. Your

subclass customizes the copy operation by defining its own version of copyElement.

The default implementation of copyElement makes shallow copies of all the

nondependent properties. copyElement copies each property value and assigns it to the

new (copied) property. If a property value is a handle object, copyElement copies the

handle, but not the underlying data.

To implement different copy behavior for different properties, override copyElement. For

example, the copyElement method of the SpecializedCopy class:

• Creates a new class object


• Copies the value of Prop1 to the new object


• Reinitializes the default value of Prop2 by adding a timestamp when the copy is made

7 Value or Handle Class — Which to Use