Out of 4 concepts, which 3 C++ Follow?

TCS,

inheritence with example

function overridind means and simple program

what is mean by design pattern

What do we mean by a hidden argument in a function?

TCL,

What do we mean by a hidden argument in C++?

What is the use of unnamed namespaces in OOPS? The only advantage I know is that they dont need the scope resolution operator while accessing them. I want to know some other advantages of unnamed namespaces...

What is a macro? And how is a macro same as a template?

What is the default size allocated for array in the statement if size not specified " int a[] "

CTS,

What is the difference between Home and $Home?

TCS,

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

difference between abstraction and encapsulation with progarammatic eg. hi,just recently i went for an interview .The interviewer asked what is the difference between abstraction and encapsulation with programmatic eg. I gave the answer as encapsulation mean hiding the relevant data which is not useful for the user, eg a electric fan .hiding the information how the electricity is converted into machanical energy. abtraction showing only the relevant data to the user eg electric fan. it look ,its color ,it design etc only relevant data. Then the interviewer asked me, give me some programmic eg .I Said Let assume a web form having control like textbox,button etc. The user can view textbox,button etc this is the eg of abstraction and when the user click on the button how he is redirected is not known by the user is the eg of the encapsulation. Am I Correct .was the answer given by me is perfect .now i am planing to go for an another interview should i give the same answer.IF not please suggest me a better answer.with some good eg Please help

What is the use of fflush(stdin) in c++?

HCL,

Why is it so that we can have virtual constructors but we cannot have virtual destructors?

Which keyword is written to use a variable declared in one class in the other class?

TCS,