Solved 100+ MCQs Object-oriented Programming

Solved 100+  MCQs Object-oriented Programming:

--------------------------------------------------------------------------------------------- What will be the output of following program? #include<iostream.h> void main() { float x; x=(float)9/2; cout<<x; } 4.5 4.0 4 5 __________________________________________________________________________________

The term __________ means the ability to take many forms.  Inheritance Polymorphism Member function Encapsulation       _____________________________________________________________________________________

Runtime polymorphism is achieved by  Friend function Virtual function Operator overloading Function overloading       _____________________________________________________________________________________

Access to private data  Restricted to methods of the same class Restricted to methods of other classes Available to methods of the same class and other classes Not an issue because the program will not compile       _____________________________________________________________________________________

Additional information sent when an exception is thrown may be placed in  The throw keyword The function that caused the error The catch block An object of the exception class       _____________________________________________________________________________________

A static data member is given a value  Within the class definition Outside the class definition When the program is exeuted Never

_____________________________________________________________________________________

In a class specifier ,data or function designated private are accessible  To any function in the program Only if you the password To member functions of that class Only to public members of the class       _____________________________________________________________________________________

Which of the statements are true ? I. Function overloading is done at compile time. II. Protected members are accessible to the member of derived class. III. A derived class inherits constructors and destructors. IV. A friend function can be called like a normal function. V. Nested class is a derived class. I, II, III II, III, V III, IV, V I, II, IV       _____________________________________________________________________________________

At which point of time a variable comes into existence in memory is determined by its  Scope Storage class Data type All of the above       _____________________________________________________________________________________

When the compiler cannot differentiate between two overloaded constructors, they are called  Overloaded Destructed Ambiguous Dubious       _____________________________________________________________________________________

The actual source code for implementing a template function is created when  The declaration of function appears. The function is invoked. The definition of the function appears. None of the above.       _____________________________________________________________________________________

Usually a pure virtual function  Has complete function body Will never be called Will be called only to delete an object Is defined only in derived class       _____________________________________________________________________________________

Which of the following is the valid class declaration header for the derived class d with base classes b1 and b2? class d : public b1, public b2 class d : class b1, class b2 class d : public b1, b2 class d : b1, b2       _____________________________________________________________________________________

The process of extracting the relevant attributes of an object is known as  Polymorphism Inheritence Abstraction Data hiding       _____________________________________________________________________________________

What features make C++ so powerful ? Easy implementation Reusing old code Reusing old code All of the above       _____________________________________________________________________________________

Which of the following operator can be overloaded through friend function? -> = ( ) *       _____________________________________________________________________________________

The keyword friend does not appear in  The class allowing access to another class The class desiring access to another class The private section of a class The public section of a class       _____________________________________________________________________________________

Exception handling is targeted at  Run-time error Compile time error Logical error All of the above       _____________________________________________________________________________________

Function templates can accept  Any type of parameters Only one parameter Only parameters of the basic type Only parameters of the derived type       _____________________________________________________________________________________

If the variable count exceeds 100, a single statement that prints “Too many” is if (count<100) cout << “Too many”; if (count>100) cout >> “Too many”; if (count>100) cout << “Too many”; None of these.       _____________________________________________________________________________________

The mechanism that binds code and data together and keeps them secure from outside world is known as Abstraction Inheritance Encapsulation Polymorphism       _____________________________________________________________________________________

The operator << when overloaded in a class must be a member function must be a non member function can be both (A) & (B) above cannot be overloaded       _____________________________________________________________________________________

To access the public function fbase() in the base class, a statement in a derived class function fder() uses the statement.fbase(); fbase(); fder(); base::fbase(); der::fder();       _____________________________________________________________________________________

In which case is it mandatory to provide a destructor in a class?  Almost in every class Class for which two or more than two objects will be created Class for which copy constructor is defined Class whose objects will be created dynamically       _____________________________________________________________________________________

_________ members of a base class are never accessible to a derived class.  Public Private Protected A,B and C       _____________________________________________________________________________________

What is the error in the following code? class t { virtual void print(); } No error Function print() should be declared as static. Function print() should be defined. Class t should contain data members.       _____________________________________________________________________________________

It is possible to declare as a friend  A member function A global function A class All of the above       _____________________________________________________________________________________

A struct is the same as a class except that  There are no member functions All members are public Cannot be used in inheritance hierarchy It does have a this pointer       _____________________________________________________________________________________

C++ was originally developed by Clocksin and Melish Donald E.Knuth Sir Richard Hadlee Bjarne Stroustrup       _____________________________________________________________________________________

What is the output of the following code char symbol[3]={‘a’,‘b’,‘c’}; for (int index=0; index<3; index++) cout << symbol [index]; a b c “abc” abc ‘abc’       _____________________________________________________________________________________

If we create a file by ‘ifstream’, then the default mode of the file is _________ ios :: out ios :: in ios :: app ios :: binary       _____________________________________________________________________________________

The following can be declared as friend in a class  An object A class A public data member A private data member       _____________________________________________________________________________________

The polymorphism can be characterized by the phrase  One interface,multiple methods Multiple interfaces,one method One interface,one method None of the above       _____________________________________________________________________________________

A virtual class is the same as  An abstract class A class with a virtual function A base class None of the above       _____________________________________________________________________________________

Member functions, when defined within the class specification  Are always inline Are not inline Are inline by default, unless they are too big or too complicated Are not inline by default.       _____________________________________________________________________________________

Assume that we have constructor functions for both base class and derived class. Now consider the declaration in main( ). Base * P = New Derived; in what sequence will the constructor be called ? Derived class constructor followed by Base class constructor. Base class constructor followed by derived class constructor. Base class constructor will not be called. Base class constructor will not be called.       _____________________________________________________________________________________

The operator that cannot be overloaded is ++ : : ~ ( )       _____________________________________________________________________________________

Which of the following declarations are illegal? void *ptr; char *str = “hello”; char str = “hello”; const *int p1;       _____________________________________________________________________________________

Identify the operator that is NOT used with pointers -> & * >>       _____________________________________________________________________________________

Which of the following statements is NOT valid about operator overloading?  Only existing operators can be overloaded Overloaded operator must have at least one operand of its class type The overloaded operators follow the syntax rules of the original operator None of the above       _____________________________________________________________________________________

Overloading a postfix increment operator by means of a member function takes  No argument One argument Two arguments Three arguments       _____________________________________________________________________________________

Which of the following will produce a value 10 if x = 9.7? floor(x) abs(x) log(x) ceil(x)       _____________________________________________________________________________________

Which of the following is not the characteristic of constructor?  They should be declared in the public section. They do not have return type. They can not be inherited. They can be virtual.       _____________________________________________________________________________________

You may override the class access specifiers  Public members Public and protected members Any specific class members you choose No class members       _____________________________________________________________________________________

You separated a derived class name from its access specifier with  A colon Two colons Atleast one space A semi colon       _____________________________________________________________________________________

Consider the following statements: int x = 22,y=15; x = (x>y) ? (x+y) : (x-y); What will be the value of x after executing these statements? 22 37 7 5       _____________________________________________________________________________________

A friend function to a class, C cannot access  Private data members and member functions Public data members and member functions Protected data members and member functions The data members of the derived class of C       _____________________________________________________________________________________

The members of a class by default are  Public Protected Private Mandatory to specify       _____________________________________________________________________________________

If x =5, y =2 then x ^y equals________. (where ^ is a bitwise XOR operator) 00000111 10000010 10100000 11001000

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1. UNIT – 1 (OOP Concepts and Introduction to C++)

1 In structured programming, the problem is divided into various ______.
(A) modules (B) functions
(C) structures (D) objects

2 In Object-oriented programming, the problem is divided into _____.
(A) classes & objects (B) functions
(C) structures (D) modules

3 A class is ____ datatype.
(A) primitive (B) derived
(C) user-defined (D) All of these

4 A class is a collection of ____ and _____.
(A) data-members & member functions (B) data-members, member functions and
main()
(C) data-members, member functions,
main() and include statements
(D) None of these

5 An object is ……
(A) a variable of class datatype. (B) same as a class.
(C) just like a global variable. (D) collection of data-members and
member functions.

6 Wrapping up of data & functions together in a class is known as _____.
(A) Overloading (B) Data Abstraction
(C) Polymorphism (D) Encapsulation

7 Including only necessary details and ignoring additional details while defining a class is
known as ____.
(A) Overloading (B) Data Abstraction
(C) Polymorphism (D) Encapsulation

8 Preventing direct access of data-members of the class from outside world is known as ____.
(A) Polymorphism (B) Encapsulation
(C) Data Hiding. (D) scope resolution.

9 What are cin and cout?
(A) pointers (B) functions
(C) operator (D) stream objects

10 Which header file must be included for cin and cout?
(A) stdio.h (B) conio.h
(C) iostream.h (D) Both iostream.h and conio.h

11Creating a new class using one or more existing classes is known as ____.
(A) Polymorphism (B) Encapsulation
(C) overloading (D) inheritance

12Ability of an operator or function call to take different forms is known as ____.
(A) Polymorphism (B) Encapsulation
(C) overloading (D) inheritance

Answers 1 – B 2 – A 3 – C 4 – A 5 – A 6 – D
7 – B 8 – C 9 – C 10 – C 11 – D 12 - A

UNIT – 2 (Control Flow Constructs, Input /Output and Arrays)

1 Which of the following can replace a simple if-else construct?
(A) Ternary operator (B) while loop
(C) do-while loop (D) for loop

2 Which of the following is an entry-controlled loop?
(A) do-while loop (B) while loop
(C) for loop (D) Both (B) and (C)

3 Which of the following is most suitable for a menu-driven program?
(A) do-while loop (B) while loop
(C) for loop (D) All of these

4 Consider the following loop : for(int i=0; i<5; i++) ;
What will be the value of i after this loop?
(A) It will give compilation error. (B) 5
(C) 6 (D) Some Garbage value

5 A switch construct can be used with which of the following types of variable?
(A) int (B) int, char
(C) int, float, char (D) Any basic datatype

6 Which of the following must be present in switch construct?
(A) Expression in ( ) after switch (B) default
(C) case followed by value (D) All of these

7 What is the effect of writing a break statement inside a loop?
(A) It cancels remaining iterations. (B) It skips a particular iteration.
(C) The program terminates immediately. (D) Loop counter is reset.

8 What is the effect of writing a continue statement inside a loop?
(A) It cancels remaining iterations. (B) It skips execution of statements which
are written below it.
(C) The program terminates immediately. (D) Loop counter is reset.

9 What are cin and cout?
(A) pointers (B) functions
(C) operator (D) stream objects

10 Which header file must be included for cin and cout?
(A) stdio.h (B) conio.h
(C) iostream.h (D) Both iostream.h and conio.h

11 Which of the following is NOT correct 1D array declaration?
(A) int a[ ] = {1 , 2 , 3} ; (B) int a[5] = {1 , 2 , 3} ;
(C) int a[5] = {0} ; (D) int a[3] = {1 , 2 , 3, 4 , 5} ;

12 Which of the following is NOT correct 2D array declaration?
(A) int m[ ] [3] = {1 , 2 , 3, 4} ; (B) int m[3][ ] = {1 , 2 , 3, 4} ;
(C) int m[2][3]; (D) int m[R] [C]; (R & C are constants)

Answers

1 – A 2 – D 3 – A 4 – B 5 – B 6 – A
7 – A 8 – D 9 – C 10 – C 11 – D 12 - B