C++ Programming - OOPS Concepts - Discussion

Inheritance will acquire one class properties, but here the question is not about the class, it's about an object inside a class, so the answer is composition.

It's a part of Association, where two classes communicate each other but don't have a relationship and inside Association the form of Aggregation where two classes objects can communicate each other but one class denotes as owner and one class denotes its part for example Department has lecturers if department object destroys lecturers will exist another example Address can relate to one and more entity if people those are living on that address leave the address so the address will exist and inside aggregation, the form is composition, whether one entity lifecycle depends on another entity, means like if House and Room relationship if the house will destroy room will also destroy this called composition.

I don't know about composition please tell me, anyone, in detail about composition.

I agree, thanks @Sunil.

Composition is a HAS-A relationship. One class can hold the object of another class and also manages its life-cycle. So we can class A has a B class object.

Inheritance is IS-A relationship. Derived class is derived from the base class. So we can say that derived class is a base class (since it holds all the properties which is in base class).

I think right will be inheritance as it inherits attributes and behavior of a class to another class.

We establish composition (HAS-A) relation between classes if one object cannot exist without another object.

For ex-Student/Employee/anyone cant exist without Address.
Say Student HAS-A address
& Employee HAS-A address
class Address{}
class Student{
Address a=new Address();
}

Similarly
class Employee{
Address a=new Address();
}

The car has an engine is a composition here we are talking about some part of the car.

The car is a 4wheeler is an inheritance.

The question is very inaccurate, it should have been:.

"Of the defining object of one class as a member of another class?".

Compare this with "Of using object of one class inside another class?".

Actually "using" means to have access to an instance by any mean (even as a parameter) and call it's member functions. None of the options match this trivial functionality, but "None" was provided as an option.

Inheritance can be know by IS A relationship.

Composition is known by HAS A relationship (its basically a code reuse).