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Interview based question and answers in C plus plus lanaguage

Interview based question and answers in C plus plus lanaguage

C++ is a high level programming and object oriented programming language. This tutorial helps to learn interview based question and answers.

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1) What is Class in C++?

Ans:- Class in C++ can be defined as a collection of member function and related data under a single name. By creating object we can access function and data in the class.

2) What is member function in C++?

Ans:- The member function regulates the behavior of the class. It provides a definition for supporting various operations on data held in the form of an object.

3) What are the various basic data type available in C++?

Ans:- Char, int, float,double,Bool.

4) How Functions are classified in C++?

Ans:- User defined Function, Predefined Function

5) How many types of User defined functions in C++?

Ans:-

Function with no argument and no return value.

Function with no argument but return value.

Function with argument but no return value.

Function with argument and return value.

6) What is the difference between Function declaration and Function Prototype?

Ans:- A function definition cannot be called unless the function is declared. The function prototype and the function definition must agree exactly on the return type, the name, and the parameters.

7) What is the difference between late binding and early binding?

Ans:- The early binding (static binding) refers to compile time binding and late binding (dynamic binding) refers to runtime binding.

8) Write a C++ Program to calculate a Armstrong number.

Ans:-

int main()
{
  int origNum, num, rem, sum = 0;
  cout << "Enter a positive  integer: ";
  cin >> origNum; 
  num = origNum; 
  while(num != 0)
  {
      rem = num % 10;
      sum += rem * rem * rem;
      num /= 10;
  } 
  if(sum == origNum)
    cout << origNum << " is an Armstrong number.";
  else
    cout << origNum << " is not an Armstrong number."; 
  return 0;
}

9) What are Virtual Functions? 

Ans:- If a function with same name exists in base as well as parent class, then the pointer to the base class would call the functions associated only with the base class. However, if the function is made virtual and the base pointer is initialized with the address of the derived class, then the function in the child class would be called. 

10) What is Pure Virtual Function? 

Ans:- Pure Virtual Function does not have a implementation part, but it’s declared as ‘0’ in the declaration Part. 

11) Name some of the commonly used manipulators in C++?

Ans:- Setw,setprecision,setf,endl 

12) Can we define a Class without creating Constructor?

Ans:- Yes we can create a Class without creating Constructor. 

13) Explain the advantages of using Friend Classes?

Ans:- When private data members need to be accessed and used by 2 classes simultaneously. In these kind of situations we will use friend functions which have an access to the private data members of both the classes. Friend functions need to be declared as ‘friend’ in both the classes.

14) Write a C++ program to remove all characters except alphabets?

Ans:-

#include <iostream>

void main() {
    string line;
    cout << "Enter a string: ";
    getline(cin, line); 
    for(int i = 0; i < line.size(); ++i)
    {
        if (!((line[i] >= 'a' && line[i]<='z') || (line[i] >= 'A' && line[i]<='Z')))
        {
            line[i] = '\0';
        }
    }
    cout << "Output String: " << line;   
   } 

15)Write a C++ Program to find the largest among ‘N’ numbers.

Ans:-#include <iostream>
void main()
{
int i,n,m;
cout <<"Enter the total number \n";
cin >>n;
cout <<"The total number of array is \n"<<n;
for(i=1;i<=n;i++)
cin >>a[i];
cout <<"The entered array is \n";
for(i=1;i<=n;i++)
cout <<"\n"<<a[i];
m = a[1];
for(i=2;i<=n;i++)
{
if(m<a[i])
m = a[i];
}
cout <<"The largest number is \n"<< m;
getch()
} 

16)Write a C++ Program to Calculate Factorial of a number using Recursion

Ans:-
#include<iostream>
int factorial(int n);
void main()
{
    int n;
    cout << "Enter a positive integer: ";
    cin >> n;
    cout << "Factorial of " << n << " = " << factorial(n);
}
 
int factorial(int n)
{
    if(n > 1)
        return n * factorial(n - 1);
    else
        return 1;
}

17) What is the difference between "calloc" and "malloc"?

Ans:- calloc and malloc are used for dynamic memory allocation. Calloc initializes the memory locations to zero by default but malloc memory contains garbage values. 

18) What is a pointer?

Ans:-Pointers are variables which stores the address of another variable. 

19) What are the uses of a pointer?

Ans:-Pointer is used in the following cases

  It is used to access array elements.

  It is used for dynamic memory allocation.

  It is used in Call by reference.

  It is used in data structures like trees, graph, linked list etc 

20) Does C++ support multilevel and multiple inheritance?

Ans:- Yes

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Comments

Priya

Very useful.nice.

Comments

jaya

This interview based tutorial questions are very useful for us.