Question 1

What is the data structures used to perform recursion?

Accepted Answer

Stack Because of its LIFO (Last In First Out) property it remembers its ‘caller’ so knows whom to return when the function has to return Recursion makes use of system stack for storing the return addresses of the function calls Every recursive function has its equivalent iterative (non-recursive) function Even when such equivalent iterative procedures are written, explicit stack is to be used

Question 2

Define void pointer using C++.?

Accepted Answer

In C++, void represents the absence of type, so void pointers are pointers that point to a value that has no type The void pointers can point to any data type You can declare void pointer as follows: void *p;

Question 3

What is C++

Accepted Answer

C++ is created by Bjarne Stroustrup of AT&T Bell Labs as an extension of C, C++ is an object-oriented computer language used in the development of enterprise and commercial applications Microsoft’s Visual C++ became the premier language of choice among developers and programmers

Question 4

What are the basic concepts of object oriented programming?

Accepted Answer

It is necessary to understand some of the concepts used extensively in object oriented programmingThese include Objects Classes Data abstraction and encapsulation Inheritance Polymorphism Dynamic Binding Message passing

Question 5

What are the features of C++ different from C?

Accepted Answer

All the features of C are similiar to C++ except some features, such as polymorphism, operator overloading which are supported in C++ but not in C language Both C and C++ language is similiar in their functionality but C++ provides with more tools and options

Question 6

what is the use of virtual destructor in c++?

Accepted Answer

A destructor is automatically called when the object is destroyed A virtual destructor in C++ is used primarily to prevent resource leaks by performing a clean-up of the object

Question 7

What do you mean by reference variable in c++?

Accepted Answer

A reference variable provides an alias to a previously defined variable Data -type & reference-name = variable name

Question 8

What are storage qualifiers in C++ ?

Accepted Answer

ConstKeyword indicates that memory once initialized, should not be altered by a program Volatile keyword indicates that the value in the memory location can be altered even though nothing in the program Mutable keyword indicates that particular member of a structure or class can be altered even if a particular structure variable, class, or class member function is constant

Question 9

What is copy constructor?

Accepted Answer

Copy constructor is a constructor function with the same name as the class and used to make deep copy of objects

Question 10

What is default constructor?

Accepted Answer

A default constructor is a constructor that either has no parameters, or if it has parameters, all the parameters have default values

Question 11

What is dynamic binding?

Accepted Answer

Dynamic binding (also known as late binding) means that the code associated with a given procedure call is not known until the time of the call at run timeIt is associated with polymorphism and inheritance

Question 12

What is namespace?

Accepted Answer

The C++ language provides a single global namespaceNamespaces allow to group entities like classes, objects and functions under a name

Question 13

What do you mean by late binding?

Accepted Answer

Late binding refers to function calls that are not resolved until run time Virtual functions are used to achieve late binding When access is via a base pointer or reference, the virtual function actually called is determined by the type of object pointed to by the pointer

Question 14

What do you mean by early binding?

Accepted Answer

Early binding refers to the events that occur at compile time Early binding occurs when all information needed to call a function is known at compile time Examples of early binding include normal function calls, overloaded function calls, and overloaded operators The advantage of early binding is efficiency

Question 15

What do you mean by multiple inheritance in C++ ?

Accepted Answer

Multiple inheritance is a feature in C++ by which one class can be of different types Say class teaching Assistant is inherited from two classes say teacher and Student

Question 16

What is the difference between realloc() and free()?

Accepted Answer

The free subroutine frees a block of memory previously allocated by the malloc subroutine Undefined results occur if the Pointer parameter is not a valid pointer If the Pointer parameter is a null value, no action will occur The realloc subroutine changes the size of the block of memory pointed to by the Pointer parameter to the number of bytes specified by the Size parameter and returns a new pointer to the block The pointer specified by the Pointer parameter must have been created with the malloc, calloc, or realloc subroutines and not been deallocated with the free or realloc subroutines Undefined results occur if the Pointer parameter is not a valid pointer

Question 17

What is the difference between class and structure?

Accepted Answer

Structure: Initially (in C) a structure was used to bundle different type of data types together to perform a particular functionality But C++ extended the structure to contain functions also The major difference is that all declarations inside a structure are by default public Class: Class is a successor of Structure By default all the members inside the class are private

Question 18

What is the output of this program? #include using namespace std; int main() { int arr[] = {4, 5, 6, 7}; int *p = (arr + 1); cout << arr; return 0; }

Accepted Answer

As we couted to print only arr, it will print the address of the array.

Question 19

What is the output of this program? #include using namespace std; struct sec { int a; char b; }; int main() { struct sec s ={25,50}; struct sec *ps =(struct sec *)&s; cout << ps->a << ps->b; return 0; }

Accepted Answer

In this program, We are dividing the values of a and b, printing it.

Question 20

What is the output of this program? #include using namespace std; void fun(int x, int y) { x = 20; y = 10; } int main() { int x = 10; fun(x, x); cout << x; return 0; }

Accepted Answer

In this program, we called by value so the value will not be changed, So the output is 10

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