C++ Interview Questions and Answers - DoAnswers.com

C++ is an enhanced version of the C language. C++ includes everything that is part of C and adds support for object- oriented programming (OOP). In addition, C++ also contains many improvements and features that make it a "better C", independent of object oriented programming. C++ is actually an extendible language since we can define new types in such a way that they act just like the predefined types which are part of the standard language. If you just use C++ as a better C, you will not be using all of its power. Like any quality tool, C++ must be used the way it was designed to be used to exploit its richness. Some of the new features include encapsulation, inline function calls, overloading operators, inheritance and polymorphism. I am not going to explain what they mean here as that would simply take me away from my purpose here, but you can refer to any good C++ book or the C++ FAQ for more information.

C++ Language Interviews are getting tough these days as the technology grows faster. To get through the C++ Language interview one needs to update him/herself in a regular manner. Having said that, just before the interview, it is very important to have a quick glance of the reputed C++ Language questions and answers to make yourself comfortable during the interview process. This is where DoAnswers.com helps you in renewing yourself on C++ Language and various other technologies interview preparation.

A dangling pointer arises when you use the address of an object after its lifetime is over. This may occur in situations like returning addresses of the automatic variables from a function or using the address of the memory block after it is freed. The following code snippet shows this: class Sample { public: int *ptr; Sample(int i) { ptr = new int(i); } ~Sample() { delete ptr; } void PrintVal() { cout << "The value is " << *ptr; } }; void SomeFunc(Sample x) { cout << "Say i am in someFunc " << endl; } int main() { Sample s1 = 10; SomeFunc(s1); s1.PrintVal(); } In the above example when PrintVal() function is called it is called by the pointer that has been freed by the destructor in SomeFunc.

A modifier, also called a modifying function is a member function that changes the value of at least one data member. In other words, an operation that modifies the state of an object. Modifiers are also known as ?mutators?. Example: The function mod is a modifier in the following code snippet: class test { int x,y; public: test() { x=0; y=0; } void mod() { x=10; y=15; } };

A node class is a class that, relies on the base class for services and implementation, provides a wider interface to the users than its base class, relies primarily on virtual functions in its public interface depends on all its direct and indirect base class can be understood only in the context of the base class can be used as base for further derivation can be used to create objects. A node class is a class that has added new services or functionality beyond the services inherited from its base class.

It is an object of some class whose purpose is to indicate that a real object of that class

The simple answer is that a virtual destructor is one that is declared with the virtual attribute. The behavior of a virtual destructor is what is important. If you destroy an object through a baller or reference to a base class, and the base-class destructor is not virtual, the derived-class destructors are not executed, and the destruction might not be comple

A class that has no functionality of its own. Its member functions hide the use of a third party software component or an object with the non-compatible interface or a non-object-oriented implementation.

Incomplete types refers to pointers in which there is non availability of the implementation of the referenced location or it points to some location whose value is not available for modification. int *i=0x400 // i points to address 400 *i=0; //set the value of memory location pointed by i. Incomplete types are otherwise called uninitialized pointers.

A class that is used to traverse through the objects maintained by a container class. There are five categories of iterators: input iterators, output iterators, forward iterators, bidirectional iterators, random access. An iterator is an entity that gives access to the contents of a container object without violating encapsulation constraints. Access to the contents is granted on a one-at-a-time basis in order. The order can be storage order (as in lists and queues) or some arbitrary order (as in array indices) or according to some ordering relation (as in an ordered binary tree). The iterator is a construct, which provides an interface that, when called, yields either the next element in the container, or some value denoting the fact that there are no more elements to examine. Iterators hide the details of access to and update of the elements of a container class. The simplest and safest iterators are those that permit read-only access to the contents of a container class.

If two base classes have no overlapping methods or data they are said to be independent of, or orthogonal to each other. Orthogonal in the sense means that two classes operate in different dimensions and do not interfere with each other in any way. The same derived class may inherit such classes with no difficulty.