90+ Object Oriented Programming (OOP) Solved MCQs

These multiple-choice questions (MCQs) are designed to enhance your knowledge and understanding in the following areas: Computer Science Engineering (CSE) , Information Technology Engineering (IT) , Bachelor of Science in Computer Science TY (BSc CS) , Bachelor of Science in Computer Science (BSc CS) , Programming Languages .

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1.	Every class has at least one constructor function, even when none is declared.
A.	true
B.	false
Answer» A. true

discuss ⁽¹⁾

2.	Can constructors be overloaded?
A.	true
B.	false
Answer» A. true

3.	What is the difference between struct and class in terms of Access Modifier?
A.	by default all the struct members are private while by default class members are public.
B.	by default all the struct members are protected while by default class members are private.
C.	by default all the struct members are public while by default class members are private.
D.	by default all the struct members are public while by default class members are protected.
Answer» C. by default all the struct members are public while by default class members are private.

4.	An abstract class can be instantiated.
A.	true
B.	false
Answer» B. false

5.	The default access level assigned to members of a class is
A.	private
B.	public
C.	protected
D.	needs to be assigned
Answer» A. private

6.	There is nothing like a virtual constructor of a class.
A.	true
B.	false
Answer» B. false

7.	Which of the following operators allow defining the member functions of a class outside the class?
A.	::
B.	?
C.	:?
D.	%
Answer» A. ::

8.	Which type of class has only one unique value for all the objects of that same class?
A.	this
B.	friend
C.	static
D.	both a and b
Answer» C. static

9.	Which one of the following is not a fundamental data type in C++?
A.	float
B.	string
C.	int
D.	char
Answer» B. string

10.	What is a constructor?
A.	a class automatically called whenever a new object of this class is created.
B.	a class automatically called whenever a new object of this class is destroyed.
C.	a function automatically called whenever a new object of this class is created.
D.	a function automatically called whenever a new object of this class is destroyed.
Answer» C. a function automatically called whenever a new object of this class is created.

11.	Under what conditions a destructor destroys an object?
A.	scope of existence has finished
B.	object dynamically assigned and it is released using the operator delete.
C.	program terminated.
D.	both a and b.
Answer» D. both a and b.

12.	When class B is inherited from class A, what is the order in which the constructers of those classes are called
A.	class a first class b next
B.	class b first class a next
C.	class b's only as it is the child class
D.	class a's only as it is the parent class
Answer» A. class a first class b next

17.	Classes are useful because they
A.	can closely model objects in the real world.
B.	permit data to be hidden from other classes.
C.	bring together all aspects of an entity in one place.
D.	options a, b and c
Answer» D. options a, b and c

18.	For the object for which it was called, a const member function
A.	can modify both const and non-const member data.
B.	can modify only const member data.
C.	can modify only non-const member data.
D.	can modify neither const nor non-const member data.
Answer» D. can modify neither const nor non-const member data.

19.	Dividing a program into functions
A.	is the key to object-oriented programming.
B.	makes the program easier to conceptualize.
C.	may reduce the size of the program.
D.	option b and c
Answer» D. option b and c

20.	An expression
A.	usually evaluates to a numerical value.
B.	may be part of a statement.
C.	always occurs outside a function.
D.	option a and b
Answer» D. option a and b

13.	Which one of the following is not a valid reserved keyword in C++?
A.	explicit
B.	public
C.	implicit
D.	private
Answer» C. implicit

14.	Variables declared in the body of a particular member function are known as data members and can be used in all member functions of the class.
A.	true
B.	false
Answer» B. false

15.	In a class definition, data or functions designated private are accessible
A.	to any function in the program.
B.	only if you know the password.
C.	to member functions of that class.
D.	only to public members of the class.
Answer» C. to member functions of that class.

16.	A member function can always access the data
A.	in the object of which it is a member.
B.	in the class of which it is a member.
C.	in any object of the class of which it is a member.
D.	in the public part of its class.
Answer» A. in the object of which it is a member.

21.	A variable of type char can hold the value 301.
A.	true
B.	false
Answer» B. false

22.	In an assignment statement, the value on the left of the equal sign is always equal to the value on the right.
A.	true
B.	false
Answer» B. false

23.	It’s perfectly all right to use variables of different data types in the same arithmetic expression.
A.	true
B.	false
Answer» A. true

24.	A function’s single most important role is to
A.	give a name to a block of code.
B.	reduce program size.
C.	accept arguments and provide a return value.
D.	help organize a program into conceptual units.
Answer» D. help organize a program into conceptual units.

25.	A function argument is
A.	a variable in the function that receives a value from the calling program.
B.	a way that functions resist accepting the calling program’s values.
C.	a value sent to the function by the calling program.
D.	a value returned by the function to the calling program.
Answer» C. a value sent to the function by the calling program.

26.	When arguments are passed by value, the function works with the original arguments in the calling program.
A.	true
B.	false
Answer» B. false

90+ Object Oriented Programming (OOP) Solved MCQs

Every class has at least one constructor function, even when none is declared.

Can constructors be overloaded?

What is the difference between struct and class in terms of Access Modifier?

An abstract class can be instantiated.

The default access level assigned to members of a class is

There is nothing like a virtual constructor of a class.

Which of the following operators allow defining the member functions of a class outside the class?

Which type of class has only one unique value for all the objects of that same class?

Which one of the following is not a fundamental data type in C++?

What is a constructor?

Under what conditions a destructor destroys an object?

When class B is inherited from class A, what is the order in which the constructers of those classes are called

Which one of the following is not a valid reserved keyword in C++?

Variables declared in the body of a particular member function are known as data members and can be used in all member functions of the class.

In a class definition, data or functions designated private are accessible

A member function can always access the data

Classes are useful because they

For the object for which it was called, a const member function

Dividing a program into functions

An expression

A variable of type char can hold the value 301.

In an assignment statement, the value on the left of the equal sign is always equal to the value on the right.

It’s perfectly all right to use variables of different data types in the same arithmetic expression.

A function’s single most important role is to

A function argument is

When arguments are passed by value, the function works with the original arguments in the calling program.

Which of the following can legitimately be passed to a function?

How many values can be returned from a function?

When a function returns a value, the entire function call can appear on the right side of the equal sign and be assigned to another variable.

When an argument is passed by reference

Overloaded functions

A static local variable is used to

In C++ there can be an array of four dimensions.

When an array name is passed to a function, the function

The compiler will complain if you try to access array element 14 in a 10-element array.

The extraction operator (>>) stops reading a string when it encounters a space.

You can read input that consists of multiple lines of text using

You should prefer C-strings to the Standard C++ string class in new programs.

Objects of the string class

Can destuctors be private in C++?

What is value of size?

What value will be printed for data.i?

What is the compilation error for this program?

What will be the output of the program?

What is the output of the program?

Which function will change the state of the object?

What will be the output of the following program?

The only integer that can be assigned directly to a pointer is

Which of the following feature is not supported by C++?

The operators that cannot be overloaded is

27.	Which of the following can legitimately be passed to a function?
A.	a constant
B.	a variable
C.	a structure
D.	all of the above
Answer» D. all of the above

28.	How many values can be returned from a function?
A.	0
B.	1
C.	2
D.	3
Answer» B. 1

30.	When an argument is passed by reference
A.	a variable is created in the function to hold the argument’s value.
B.	the function cannot access the argument’s value.
C.	a temporary variable is created in the calling program to hold the argument’s value.
D.	the function accesses the argument’s original value in the calling program.
Answer» D. the function accesses the argument’s original value in the calling program.

31.	Overloaded functions
A.	are a group of functions with the same name.
B.	all have the same number and types of arguments.
C.	make life simpler for programmers.
D.	a and c
Answer» D. a and c

32.	A static local variable is used to
A.	make a variable visible to several functions.
B.	make a variable visible to only one function.
C.	retain a value when a function is not executing.
D.	b and c
Answer» D. b and c

34.	When an array name is passed to a function, the function
A.	accesses exactly the same array as the calling program.
B.	refers to the array using a different name than that used by the calling program.
C.	refers to the array using the same name as that used by the calling program.
D.	a and b
Answer» D. a and b

37.	You can read input that consists of multiple lines of text using
A.	the normal cout <<combination.
B.	the cin.get() function with one argument.
C.	the cin.get() function with two arguments.
D.	the cin.get() function with three arguments.
Answer» D. the cin.get() function with three arguments.

39.	Objects of the string class
A.	are zero-terminated.
B.	can be copied with the assignment operator.
C.	do not require memory management.
D.	both b and c
Answer» D. both b and c

40.	Can destuctors be private in C++?
A.	yes
B.	no
Answer» A. yes

42.	What value will be printed for data.i?
A.	10 220.5 230.5 unpredictable value
B.	220
C.	230.5
D.	unpredictable value
Answer» D. unpredictable value