Question

Is it possible to return an object from a static method in C++ like there is in Java? I am doing this:

class MyMath {
    public:
       static MyObject calcSomething(void);
    private:
};

And I want to do this:

int main() { 
    MyObject o = MyMath.calcSomething(); // error happens here
}

There are only static methods in the MyMath class, so there’s no point in instantiating it. But I get this compile error:

MyMath.cpp:69: error: expected primary-expression before ‘.’ token

What am I doing wrong? Do I have to instantiate MyMath? I would rather not, if it is possible.

Answer 1

Use :: instead of .

MyObject o = MyMath::calcSomething();

When you are calling the method without the object of the class you should use :: notation. You may also call static method via class objects or pointers to them, in this case you should use usual . or -> notation:

MyObject obj;
MyObject* p = new MyObject();

MyObject::calcSomething();
obj.calcSomething();
p->calcSomething();