what is the abstract class,interface ,its difference with a programatic eg.?
hi,recently i went for an interview they ask me what is abstract class ,interface and its difference
I said abstract class contain abstact method ,abstract method is a method with no body.Abstract class cannot be instantiated.Abstract class is a base class it required derived class for the implementation of method.
Interface is a syntactical contract that all derived class should follow
it define properties ,method,events which are known as member of interface.
Then They asked me what is the difference between them. I said
abstract class interface
1.abstact class can implement method 1.interface cant
2.abstact class can contain constructor, 2.interface cant
destructor
3.abstract class cannot support multiple 3.interface support
inheritance
etc
Then they said some different answer I said dont no.
Then they ask me when i should make abstract class for an project and when
i should make interface.
I said if suppose there is two class which must be having method with different logic then we sholud make abstract class.
and if suppose we have two class having method .with different logic then we can make interface .
Am i correct with my explaination.if not correct me .please provide me that when should we create abstract class and interface and what is difference .please help me
Answer / sachinmundhra
Abstract class will have a pure virtual function. A virtual
function having no body.
virtual void display() = 0 ;
| Is This Answer Correct ? | 0 Yes | 3 No |
Contrast OOP and SOA. What are tenets of each?
1 Answers Siebel Systems, Wipro,
how much classes are used in c++
What is Hashing and how is it done? Pictorial form?
why c++ is called OOPS? waht is inherutance? what is compiler?
Who invented oop?
What is abstraction?
why oops need in programming
what is object slicing?
Question In a class, there is a reference or pointer of an object of another class embedded, and the memory is either allocated or assigned to the new object created for this class. In the constructor, parameters are passed to initialize the data members and the embedded object reference to get inialized. What measures or design change should be advised for proper destruction and avioding memory leaks, getting pointers dangling for the embedded object memory allocation? Please suggest. Question Submitted By :: Sunil Kumar I also faced this Question!! Rank Answer Posted By Re: In a class, there is a reference or pointer of an object of another class embedded, and the memory is either allocated or assigned to the new object created for this class. In the constructor, parameters are passed to initialize the data members and the embedded object reference to get inialized. What measures or design change should be advised for proper destruction and avioding memory leaks, getting pointers dangling for the embedded object memory allocation? Please suggest. Answer # 1 use copy constructors 0 Shanthila There is something to be taken care in destructor, in copy constructor, suppose the memory is assigned to the embedded member object pointer with the parameter passed value, but if some other objects of different class also are pointing to this memory, then if some one deletes the object then this class member pointer object will become dangling, or if the object is not deleted properly then there will be memory leak. Please suggest the design change required to handle or avoid this situation
How do you explain polymorphism?
suppose A is a base class and B is the derved class. Both have a method foo which is defined as a virtual method in the base class. You have a pointer of classs B and you typecast it to A. Now when you call pointer->foo, which method gets called? The next part of the question is, how does the compiler know which method to call?
What normal C constructs work differently in C++?