Thread: converting from java

is there an equivilent of interfaces in c++?

Hmm... COM interfaces are interfaces. I don't really know Java so I don't know what interfaces it has.

how do you extend classes?

Put a ':' after the class. Example:

class Car : Vehicle
{
long cDoors;
}

how do you extend more than one class?

??

how do you use null?

NULL is the same as 0. It is often used to initialize pointers.

how do you return a pointer?

From a function:

char* func()
{
char* pointer;
return pointer;
}

returns a char pointer.

is there any way of using references instead?

Returning references:

char& func()
{
char c = new char;
return c;
}

Although I don't think references works the same in C++ as in Java. Correct me if I'm wrong.

is memory allocation (malloc?) critical to learn (am i going to kill my computer if i dont learn to use it?)?

It is important but it's really easy also. Using the 'new' and 'delete' are faster than malloc. It's just simple:

char* pointer = new char[1000];
delete pointer;

what collections (preferably linked lists) are available or do I have to make my own?

There are vectors, etc. but I would do my own. Preferably, I would do template classes for linked lists.

>is there an equivilent of interfaces in c++?

You have abstract base classes that you could use instead.



>how do you extend classes?

class derived : public base
{
};

where derived and base are your class names


>how do you extend more than one class?

class derived : public base1, base2
{
};



>how do you use null?

Same as in Java: CObject* pObject = NULL;


>how do you return a pointer?

CObject* function( COBject* o )
{
o->Method();
return o;
}


>is there any way of using references instead?

CObject& function( COBject& o )
{
o.Method();
return o;
}


>is memory allocation (malloc?) critical to learn

No. Use new and delete. The difference to Java however
IS critical to learn. You don't need 'new' with anything
non-dynamic. If you need exactly one string, no need to
'new' it. On the other hand, keep good track of everything
created with new, because it's your job to make sure it
gets delete'd again.