Question

I am doing Box2D programming, and heads up, I am a total noob to C++ and C. I am an Objective-C guy, and that is why it is becoming really hard for me to understand the language. Especially:

->

Basically I understand that this is used for referencing different methods or functions or variables/properties like below:

body->GetWorld()->DestroyBody(body);

So is this equivalent to dot notation in Objective-C:

// made up example
[body.world destroyBody];

or

[self destroyBody:body.world];

Or something similar? I really don’t understand this. Can someone give me a heads up on what this is. Thanks!

Answer 1

I don’t know Objective-C, but I can explain difference between -> and . in C and C++, hope that helps.

. is operator that allows you to access member of struct/class instance. a->b is the same as (*a).b – so it first dereferences the pointer, then accesses member of instance that the pointer was pointing to.

Also, there is a case that Luchian has mentioned – overloading of operator->() of given class. In case when class you are using does overload this operator, the behavior will be different, defined by the class – it can return virtually everything it wants.