function call without creating object

[Eric Kaplan]

in C++ you can call function / methods without creating an object of
that Class?

like the the following, it calls Update() + Draw() functions by Class
name CInterfaceGroup + CContainer.

In Java, one can only call method by Class name if it is static
method.

In C++, you can call any function without creating an Object like -
CContainer * cc = new CContainer;
cc->Draw();

=========================

CGraphicsGroup::~CGraphicsGroup() {
}

void CGraphicsGroup::Create() {

}

void CGraphicsGroup::Update() {
CInterfaceGroup::Update();
}

void CGraphicsGroup:raw() {
CContainer:raw();
}

 

[hurcan solter]

in C++ you can call function / methods without creating an object of
that Class?

like the the following, it calls Update() + Draw() functions by Class
name CInterfaceGroup + CContainer.

In Java, one can only call method by Class name if it is static
method.

In C++, you can call any function without creating an Object like -
CContainer * cc = new CContainer;
cc->Draw();

=========================

CGraphicsGroup::~CGraphicsGroup() {

}

void CGraphicsGroup::Create() {

}

void CGraphicsGroup::Update() {
CInterfaceGroup::Update();

}

void CGraphicsGroup:raw() {
CContainer:raw();

}

No you can't call a member function without a object (at least the way
you do)
unless it's static.

And what was your question?

 

[Christian Hackl]

in C++ you can call function / methods without creating an object of
that Class?

[...]

In Java, one can only call method by Class name if it is static
method.

Just like in C++. However, notice the different call syntax:

class Example
{
public:
static void f();
};

Example.f(); // won't compile
Example::f(); // correct syntax

In C++, you can call any function without creating an Object like -
CContainer * cc = new CContainer;
cc->Draw();

This code *does* create an object.

 

[Joe Greer]

in C++ you can call function / methods without creating an object of
that Class?

Yes, no, maybe. Hard to tell what you are actually after, so I will
give the long form. In C++ you can call free functions, static methods
without creating an instance of a class. For example:

int f()
{
return 5;
}

class A
{
public:
static int f1()
{ return 6;
int f2() { return 7;}
};

int main()
{
f(); // OK
A::f1(); // OK
A::f2(); // Bzzzt. Not OK
A a; // Create instance of A on stack
a.f2(); // OK
}

like the the following, it calls Update() + Draw() functions by Class
name CInterfaceGroup + CContainer.

In Java, one can only call method by Class name if it is static
method.

In general, expecting things to be like Java can get you into trouble,
but in this case things are pretty much the same.

In C++, you can call any function without creating an Object like -
CContainer * cc = new CContainer;
cc->Draw();

I fail to see how this is an example of not creating an object... And
this statement is false.

joe