What is multiple inheritance explain with example?

Multiple Inheritance is a feature of C++ where a class can inherit from more than one classes. The constructors of inherited classes are called in the same order in which they are inherited. For example, in the following program, B’s constructor is called before A’s constructor.

What is virtual inheritance give example?

Virtual inheritance is a C++ technique that ensures only one copy of a base class’s member variables are inherited by grandchild derived classes.

What is multiple inheritance explain ambiguity in multiple inheritance with example?

The ambiguity that arises when using multiple inheritance refers to a derived class having more than one parent class that defines property[s] and/or method[s] with the same name. For example, if ‘C’ inherits from both ‘A’ and ‘B’ and classes ‘A’ and ‘B’, both define a property named x and a function named getx().

Is Vtable inherited?

Unlike the *this pointer, which is actually a function parameter used by the compiler to resolve self-references, *__vptr is a real pointer. Consequently, it makes each class object allocated bigger by the size of one pointer. It also means that *__vptr is inherited by derived classes, which is important.

What do you mean by multiple inheritance?

Multiple inheritance is a feature of some object-oriented computer programming languages in which an object or class can inherit characteristics and features from more than one parent object or parent class.

When should you use virtual inheritance?

Virtual inheritance is used when we are dealing with multiple inheritance but want to prevent multiple instances of same class appearing in inheritance hierarchy. From above example we can see that “A” is inherited two times in D means an object of class “D” will contain two attributes of “a” (D::C::a and D::B::a).

What is meant by multiple inheritance?

Where is vtable memory stored?

In VC++, the vtable pointer stored at the beginning of the object allocation, before any member data. (Provided your class has at least one virtual member function.) There also may be multiple vtable pointers, if your class multiply-inherits from other classes with vtables.

Which is better multiple or multilevel inheritance?

Multiple Inheritance is an Inheritance type where a class inherits from more than one base class. Multilevel Inheritance is an Inheritance type that inherits from a derived class, making that derived class a base class for a new class. Multiple Inheritance is not widely used because it makes the system more complex.

How are two vtables used in C + + inheritance?

Explanation: as we saw earlier, Childhas 2 vtables – one used for Motherand Child, and the other for Father. In Father’s vtable, FatherFoo()points to a thunk, while Child’s vtable points directly to Child::FatherFoo().

How are virtual pointers used in multiple inheritance?

Class “C” and class “D” are having virtual pointers which are helping in getting necessary offset details. vptrs (virtual pointers) index a virtual table and there is a vptr for every virtual base of class. We use class “B” and class “C” object to index the virtual table through virtual pointer and get the required offset.

How are base classes embedded in virtual inheritance?

As we can see clearly in virtual inheritance base class will not be embedded in derived class only a pointer will be provided which is pointing to the base class object but in non virtual inheritance we can see a base class embedded in derived class.

How does multiple inheritance work in C + +?

As we saw in Part 1, each child class extends its parent vtable by appending entries for each new virtual method. In this post we will cover multiple inheritance, which complicates things even when only inheriting from pure-interfaces. Let’s look at the following piece of code: