Is regVar in public a variable? Why It has no data type..? And why do we use & before obj(&obj). 'Obj.regvar' i don't get it ?

Question

class MyClass {
public:
MyClass() {
regVar = 0;
};
private:
int regVar;

friend void someFunc(MyClass &obj);
};

void someFunc(MyClass &obj) {
obj.regVar = 42;
cout << obj.regVar;
}

Answer 1

regVar is private and the data type is int as declared after the constructor of MyClass:
private:
int regVar;

&obj means a reference, not to create a new obj.

obj.regVar ia setting the regVar, that is inside of MyClass.

Answer 2

@felipe cruz but why are we setting this "obj.regvar"? And What exactly is the use of the reference "&obj "

Answer 3

Use reference so the system dont create a copy of the original on the memory. As it is just passed as parameter, no need to store the parameter on the memory, just create a reference.

&obj is a MyClass type, só when you call "obj.regVar" means you are sending a menssage to set the attribute regVar in (MyClass)obj.