Question

What is the meaning of a static method in C++?
As I understand it’s the same as in Java: there is no need to create an instance of the class in order to call the static method.
As I remember, in C we used static declaration for methods in order to make them private.
How do I make private methods in C++?
Let’s say I want to calculate some calculation with a helper function:

class A{ 
  foo();
};

A::foo(){
    int a=doSomCalculations();
}

How would I define doSomecalculations so it will be as if private helper method as in Java?

Answer 1

In C++, if you don’t explicitly state that something is public, it will be private by default. So if you want foo() to be public in your class, you need to state it so.

class A{ 
public:
  foo();
private:
  void doSomCalulations();
};

A::foo(){
    int a=doSomCalculations();
}

As a comment on your C static thing, I don’t know of anything saying that static makes anything private in C. C has no notion of private and public. In C you only have struct types, and these are all public by default.

In C++ struct have all members public by default. If you want a private member in a struct, you have to explicitly state it, like so:

struct my_struct
{
int some_public_member;

private:
int my_private_member;
};

OTOH, there is static in C which means internal linkage. Perhaps you were referring to it like this.