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Interview Questions on Classes & Objects in C++ : (29)

Question: 1

//What is the output of the following C++ program ?                   
#include<iostream>

class base
{
public:
       base()
       {          
           cout<<"BCon";
       }
       ~base()
       {
	   cout<<"BDest ";
       }
};
class derived: public base
{
public:
       derived()
       {     cout<<"DCon ";
       }
       ~derived()
       {     cout<<"DDest ";
       }
};

int main()
{
derived object;
return 0; 
}

(A) Dcon DDest
(B) Dcon DDest BCon BDest
(C) BCon DCon DDest BDest
(D) BCon DCon BDes DDest

Compiler
Level: Beginner Category: classesAndobjects
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Question: 2

#include<iostream>

class Mycpp
{
    int Mycpp()
    {
       std::cout<<"Constructor";
       return 0;
     }
};

int main()
{
    Mycpp obj;
    return 0;
}

(A) Constructor
(B) 0
(C) Compilation Error
(D) Runtime Error

Compiler
Level: Beginner Category: classesAndobjects
[Posted by: | ]

Question: 3

#include<iostream>

class Mycpp
{
    
};

int main()
{
    Mycpp obj;
    return 0;
}

(A) Compilation Error - Constructor Missing
(B) Nothing would be printed
(C) Undefined
(D) In constructor

Compiler
Level: Beginner Category: classesAndobjects
[Posted by: | ]

Question: 4

Can we create Nested classes in C++?

(A) Yes
(B) No

Compiler
Level: Practitioner Category: classesAndobjects
[Posted by: | ]

Question: 5

Can we overload Constructor?

(A) Yes
(B) No

Compiler
Level: Expert Category: classesAndobjects
[Posted by: | ]

Question: 6

Can this pointer point to another class?

(A) Yes
(B) No

Compiler
Level: Practitioner Category: classesAndobjects
[Posted by: | ]

Question: 7

What is Singleton class?

(A) We can create n number of object
(B) We can create max 256 objects
(C) We can create 1 object
(D) We cant create object

Compiler
Level: Practitioner Category: classesAndobjects
[Posted by: | ]

Question: 8

Car contains Engine. Which type of relationship is it?

(A) IS-A relation
(B) HAS-A relation
(C) None of these

Compiler
Level: Practitioner Category: classesAndobjects
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Question: 9

A constructor is a special type of?

(A) class
(B) field
(C) function
(D) property

Compiler
Level: Beginner Category: classesAndobjects
[Posted by: | ]

Question: 10

//How many times will A be printed ?

class A
{

public:
    ~A(){
    std::cout <<"A";
    }
};
int main()
{
    A obj;
    obj.~A();
}

(A) 0
(B) 1
(C) 2
(D) error

Compiler
Level: Practitioner Category: classesAndobjects
[Posted by: | ]

Question: 11

Objects in C++ are created from abstract data types that encapsulate data and functions together

(A) TRUE
(B) FALSE

Compiler
Level: Beginner Category: classesAndobjects
[Posted by: | ]

Question: 12

A C++ class is almost similar to a structure

(A) True
(B) False

Compiler
Level: Beginner Category: classesAndobjects
[Posted by: | ]

Question: 13

C++ Class declarations should never be stored in their own header file

(A) True
(B) False

Compiler
Level: Beginner Category: classesAndobjects
[Posted by: | ]

Question: 14

Assume that Honda is an instance of the Car class,
and that Car class has a member function named run.
Which of the following is a correct call to the run function?

(A) Honda->run;
(B) Honda.run();
(C) run()
(D) Honda()

Compiler
Level: Beginner Category: classesAndobjects
[Posted by: | ]

Question: 15

#include <iostream>
using namespace std;
class TestingClass
{
public:
TestingClass(int x)
{
 cout << x << endl; 
}

TestingClass()
{
 cout <<"Hello!"<< endl; 
}

};
int main()
{
 TestingClass test(77);
 return 0;
}

(A) The programs runs with no output
(B) 77
(C) Hello!
(D) Hello!

Compiler
Level: Practitioner Category: classesAndobjects
[Posted by: | ]

Question: 16

A public member function may be called from a statement outside the class, is this correct?

(A) True
(B) False

Compiler
Level: Beginner Category: classesAndobjects
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Question: 17

Which member function of a class is called automatically when any object is created of that class?

(A) static function
(B) utility function
(C) constructor
(D) destructor

Compiler
Level: Beginner Category: classesAndobjects
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Question: 18

A class is a data type that is defined by the coder?

(A) True
(B) False

Compiler
Level: Beginner Category: classesAndobjects
[Posted by: | ]

Question: 19

The name of constructor is same name as?

(A) first variable name
(B) first function
(C) class name
(D) object name

Compiler
Level: Beginner Category: classesAndobjects
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Question: 20

A class can have only one constructor

(A) True
(B) False

Compiler
Level: Practitioner Category: classesAndobjects
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Question: 21

The key words private and public are access specifiers

(A) True
(B) False

Compiler
Level: Beginner Category: classesAndobjects
[Posted by: | ]

Question: 22

Destructor functions are often used to free memory that was allocated by the object

(A) TRUE
(B) FALSE

Compiler
Level: Beginner Category: classesAndobjects
[Posted by: | ]

Question: 23

The UML provides a set of standard diagrams for graphically depicting object-oriented systems

(A) True
(B) False

Compiler
Level: Beginner Category: classesAndobjects
[Posted by: | ]

Question: 24

It is possible to declare an entire class as a friend of another class

(A) True
(B) False

Compiler
Level: Practitioner Category: classesAndobjects
[Posted by: | ]

Question: 25

If a member variable is declared as one of the below, all objects of that class have access to that variable.

(A) static
(B) auto
(C) exterb
(D) register

Compiler
Level: Practitioner Category: classesAndobjects
[Posted by: | ]

Question: 26

By default, when an object is assigned to another,
each member of one object is copied to its counterpart in the other object.

(A) True
(B) False

Compiler
Level: Practitioner Category: classesAndobjects
[Posted by: | ]

Question: 27

When you derive a class from an existing class, you __ add new data and functions

(A) never
(B) must
(C) may
(D) None

Compiler
Level: Beginner Category: classesAndobjects
[Posted by: | ]

Question: 28

#include<iostream>
using namespace std;

class Test
{
private: int x, y;
public:
        Test():y(10),x(y+10)
        {
        }
        
       void print()
       {
          cout<<x<<", "<<y;
       } 
};

int main()
{
Test *a = new Test();
a->print();

delete a;

return 0;
}

(A) Compilation Error
(B) 10, 20
(C) 10, 10
(D) 10, Undfefined Value

Compiler
Level: Expert Category: classesAndobjects
[Posted by: | ]

Question: 29

What should be the output of below C++ code?

#include <iostream>

class MyClass {
public:
    void display() {
        std::cout << "I am a const object." << std::endl;
    }
};

int main() {
    const MyClass obj; 
    obj.display();
    return 0;
}
class MyClass {
public:
    std::string str;
};

(A) I am a const object.
(B) Compilation Error
(C) Runtime Error
(D) I am a const object.

Compiler
Level: Experts Category: classesAndobjects
[Posted by: | ]

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Interview Questions on Classes & Objects in C++ : (29)

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