# C++ Technical Interview Question & Answers

1.The operator >> is called Ans. a get from operator 2.What Is the default access specifier? Ans. private 3.C++ is an Ans. o...

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1.The operator >> is called

2.What Is the default access specifier?

3.C++ is an

4.Which provides support for simultaneous input and output operations

5.Predict The Output Of the Following

class base

{

public:

int bval;

base(){ bval=0;}

};

class deri:public base

{

public:

int dval;

deri(){ dval=1;}

};

void SomeFunc(base *arr,int size)

{

for(int i=0; i cout<bval;

cout<}

int main()

{

base BaseArr[5];

SomeFunc(BaseArr,5);

deri DeriArr[5];

SomeFunc(DeriArr,5);

}

{int i=10;

j=5;

k=0;

k=MAX(i++,++j);

printf(%d %d %d %d,i,j,k);

}

**Ans.a get from operator**2.What Is the default access specifier?

**Ans.private**3.C++ is an

**Ans.object oriented programming Language**4.Which provides support for simultaneous input and output operations

**Ans.Fstream**5.Predict The Output Of the Following

class base

{

public:

int bval;

base(){ bval=0;}

};

class deri:public base

{

public:

int dval;

deri(){ dval=1;}

};

void SomeFunc(base *arr,int size)

{

for(int i=0; i cout<bval;

cout<}

int main()

{

base BaseArr[5];

SomeFunc(BaseArr,5);

deri DeriArr[5];

SomeFunc(DeriArr,5);

}

**Ans. 00000****01010**
6.Which keyword is Used by C++ to represent an object that invokes a member function

**Ans. this**

7.Which Sort Uses the binary tree concept such that any number is larger than all the numbers in the Subtree

**Ans. Heap**

8.The number of passes required for sorting M records of length N using simple external sorting algorithm is

**Ans. (A) [log(N/M)]**

9.A binary search tree contains the values - 1,2,3,4,5,6,7,8. The tree is traversed in preorder and the values are printed out. What is The valid output?

**Ans. 5 3 1 2**

10.The wrapping up of data and functions into a single unit is known as

**Ans. encapsulation**

11.What are the basic run-time entities in an object oriented system

**Ans. Objects**

12.Field width operator is

**Ans. setw**

13.What is the function that is expanded in line when it is invoked

**Ans. inline function**

14.Variables declared inside the class are known as

**Ans. datamembers**

15.Dynamic allocation operator in C++ is

**Ans. new**

16.What Is the output of the following

main()

{

int x=20,y=35;

x = y++ + x++;

y = ++y + ++x;

printf("%d %d\n",x,y);

}

**Ans. 57 94**

17.Pointer to member operator is

**Ans.**

**.***

18.What is the order of the binary search algorithm?

**Ans. log n**

19.In a binary search tree if the key element is less than the root element then sub tree must be searched in

**Ans. left**

20.Find Out The output Of the following

#include

main()

{

char *p1;

char *p2;

p1=(char *) malloc(25);

p2=(char *) malloc(25);

strcpy(p1,"Latest");

strcpy(p2,"Offcampus");

strcat(p1,p2);

printf("%s",p1);

}

**Ans. LatestOffcampus**

21.Which operation is used to add an item in a queue

**Ans.write()**

22.Queue can be used to implement

**Ans.radix sort**

23.The average number of comparisons performed by the merge sort algorithm , in merging two sorted lists of length 2 is

**Ans.8/3**

24.What are the output(s) for the following ?

#define MAN(x,y) (x)>(y)?(x):(y){int i=10;

j=5;

k=0;

k=MAX(i++,++j);

printf(%d %d %d %d,i,j,k);

}

**Ans . 10 5 0**

25.The Object is not declared for which class?

Ans. Abstract

26.Data that consists of a single, non decomposable entity are known

**Ans. atomic data**

27.In how many ways is polymorphism achived in C++?

**Ans. 3**

28.In Data members is also called?

**Ans. Attribute**

29.What is the sum of degrees of all the nodes In an undirected graph

**Ans.must be even**

30.In which trie node allows only one character

**Ans. compressed**

31.What is the output of the following

void main()

{

int i;

for(i=1;i<4,i++)

switch(i)

case 1: printf("%d",i);break;

{

case 2:printf("%d",i);break;

case 3:printf("%d",i);break;

}

switch(i) case 4:printf("%d",i);

}

**Ans. 1,2,3,4**

32.A priority queue is an abstract concept like a

**Ans. list or map**

33.How Many no.of comparisons Required For merging two sorted lists of sizes m and n into a sorted list of size m+n

**Ans. O(m+n)**

34.Which strategy is used by the merge sort

**Ans. divide and conquer**

35.What is the depth of a complete binary tree with n nodes

**Ans. log2(n+1)-1**

36.Which tree is a self-balancing binary search tree

**Ans. AVL**

37.What is the minimum number of edges in a connected cyclic on n vertices?

**Ans. n**

38.An n vertex undirected graph with exactly n*(n-1)/2 edges is said to be

**Ans.Complete graph**

39.A Standard Tree Uses

**Ans. O(n) Spces**

40.The goal of operator overloading is

**Ans.To help the user of a class**

41.Which is a special method used to initialize the instance variable of a class.

**Ans.Constructor**

42.Access to private data Means?

**Ans.Restricted to methods of other classes**

43.The static member variable is initialized to?

**Ans. 0**

44.What will be the output of following program

#include<iostream.h>

void main()

{

float x;

x=(float)9/2;

cout<<x;

}

**Ans. 4.5**

44.Usually a pure Virtual Function is

**Ans. Is defined only in derived class**

45.A Class can have how many destructor?

**Ans.1**

46.The process of extracting the relevant attributes of an object is known as

**Ans. Inheritance**

47.Which diagram provides a formal graphic notation for modelling objects, classes and their relationships to one another?

**Ans. Object Diagram**

48.Which data structure allows deleting data elements from front and inserting at rear?

Ans.Queues

49.The post order traversal of a binary tree is DEBFCA. find out the pre order traversal

**Ans.ABDECF**

50.Which constructor function is designed to copy objects of the same class type?

**Ans. Copy constructor**

51.What is mechanism Which binds code and data together and keeps them secure from outside world is?

**Ans.Encapsulation**

52.Exception handling is targeted at

**Ans. Run-time error**

53.Which keyword is used to make the class friend

**Ans.Friend**

54.Where the default value of parameter have to be specified?

**Ans.Function prototype**

55.C++ was developed by

**Ans. Bjame Stroustrup**

56.Which operator that cannot be overloaded is?

**Ans. : :**

57. What is the operator which is NOT used with pointers

**Ans. >>**

58.For Which purpose we use constructor?

**Ans.Initialization**

59.What is the operator which can be overloaded through friend function

**Ans. ***

60.A class defined with in another class is