CODEWITHSUNDEEP
matlaboopobject
baxbear
baxbear

Reputation: 890

MATLAB - How to compare if two objects are the same or different

In C++ I would just compare the memory addresses of both objects. How would I do something similar in MATLAB?

Worst Case would be to have a static variable that iterates in each constructor and every object gets the current value as ID. But is there a better solution?

Thank you in advance.

@Edit: I'd like to extend this question by assuming I have some given/not changeable classes inheriting handle and overloading eq. If I want to compare two objects of this class can I somehow cast both instances to handle and use the implementation of eq of the super class?

Upvotes: 2

Views: 1218

Answers (1)

Tom
Tom

Reputation: 1125

To test that two handle objects a and b refer to the same instance, you only need to use a == b. This is the same as eq(a, b). This is the defined behaviour of == for handle objects. I.e., for handle objects, == tests for equality of instances, not equality of the values within the instances. This is different from value objects.

For this to work you need to be using handle objects (classdef myObject < handle) because it doesn't make sense to test instances of value objects.

N.B. if you also need to get some kind of instance identifier for a handle object, then you need to do something like you describe using a persistent variable. Here's an example. In that case I would make that a base class for all your objects, so you wouldn't have to copy the same code into each class. But that's unnecessary if all you want to do is test two instances.

Upvotes: 3

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