How to communicate between different classes?

[yanjie111]

I have several classes build in one project. Class A.functionA()
need call Class B.functionB(parameters...).
Do I have to create an instance of B inside the Class A source code?
I want the implementation of all the classes (A, B, C...) are independent from each other. But each class can call other class's function with some parameters. If I create every other class instances(B, C, D...) in one class (A) the data of each class instance can not be synchronized.
Is there a better way to do that?

[AdrianH]

I have several classes build in one project. Class A.functionA()
need call Class B.functionB(parameters...).
Do I have to create an instance of B inside the Class A source code?
I want the implementation of all the classes (A, B, C...) are independent from each other. But each class can call other class's function with some parameters. If I create every other class instances(B, C, D...) in one class (A) the data of each class instance can not be synchronized.
Is there a better way to do that?

There are many ways of synchronising between class instances. But what I am gathering from you question is that I think you are confusing classes with objects, and you wouldn't be the first.

A class is a conceptualisation of what an object can do, and what it is composed of. An object is a concrete instance of the class, upon which you can do the stuff you described in your class.

Where you create the instances is dependent upon what you are trying to do. Perhaps a bit more detail would clarify things.


Adrian

[yanjie111]

Thanks you. I think I should express myself more clearly.
The project consists of several modules. I designed every module as a class.
The application call class A.functionA( parameter1, ...) and the A.functionA() calls class B.functionB(parameter1, newparameter1, ...).

The application need only create an object of class A, not any other classes(B,C,...).

How can I do that in the easiest and fastest way?

[AdrianH]

Thanks you. I think I should express myself more clearly.
The project consists of several modules. I designed every module as a class.
The application call class A.functionA( parameter1, ...) and the A.functionA() calls class B.functionB(parameter1, newparameter1, ...).

The application need only create an object of class A, not any other classes(B,C,...).

How can I do that in the easiest and fastest way?

If I understand you correctly (which I’m not sure if I do), your app will create an instance of A and call a function. That function will then create an instance of B or C and call one of their functions.

Now, will the instance of B or C need to talk back to the instance of A? If so, you are going to have to pass that instance on to B or C. That or you have a global instance of A (not recommended except for under certain circumstances).

Basically, for an instance to ‘talk’ to an instance, the first instance must have a pointer or reference to the second instance.

Does this make sense to you?


Adrian