Objects of the handle class are not identical to pointers. When you pass an object to a function (whether it is a value class or a handle class), MATLAB does not immediately make a copy of the object. It is almost like it passes a pointer (but it is not a pointer). MATLAB has a complicated COW and tries not to copy the object unless it needs to. With a high level language of MATLAB you have to give up some of the control on memory management and hope MATLAB behaves in a reasonable manner.
I agree that MATLAB has its own way to manage memory.
I find another interesting thing that graphics functions, e.g., figure(), return a double number, named graphic handle, but not a figure object.
And I can not figure out where the figure object stored. Is it sotred in currenct workspace? A persistent variable in some functions? Or in a memory segment whose adress only MATLAB knows?
"then objects of Ptr will behave like pointers". If the behaviour you mean is that once you change a Ptr, all other variables that "point" to the same object are changed as well, then yes. Example:
x = Ptr;
y = x; % both x and y "point" to the same object
x.data = 2; % now y.data is 2 as well
But I would say that "reference" like the & in C++ comes nearer to what handle classes are ...
The handle class is the superclass for all classes that follow handle semantics. A handle is a reference to an object. If you copy an object's handle, MATLAB copies only the handle and both the original and copy refer to the same object data. If a function modifies a handle object passed as an input argument, the modification affects the original input object.
hmm, why not? When you pass an object by reference to a function, the function may change the underlying/referenced object. Of course only, as long as you don't pass a const reference ... Or do I remember entirely wrong, since my C++ programming is about 10 years ago by now ;-).
Da Änderungen an der Seite vorgenommen wurden, kann diese Aktion nicht abgeschlossen werden. Laden Sie die Seite neu, um sie im aktualisierten Zustand anzuzeigen.
Translated by
Website auswählen
Wählen Sie eine Website aus, um übersetzte Inhalte (sofern verfügbar) sowie lokale Veranstaltungen und Angebote anzuzeigen. Auf der Grundlage Ihres Standorts empfehlen wir Ihnen die folgende Auswahl: .
Sie können auch eine Website aus der folgenden Liste auswählen:
So erhalten Sie die bestmögliche Leistung auf der Website
Wählen Sie für die bestmögliche Website-Leistung die Website für China (auf Chinesisch oder Englisch). Andere landesspezifische Websites von MathWorks sind für Besuche von Ihrem Standort aus nicht optimiert.