C++ Online Exam

Q1: Which of the following is a C++ compiler?

A) GCC
B) Turbo Pascal
C) Clang
D) MSVC

Q2: Which C++ feature allows the same function to have different behaviors?

A) Inheritance
B) Encapsulation
C) Polymorphism
D) Abstraction

Q3: What is the use of 'this' pointer in C++?

A) Refers to base class
B) Refers to derived class
C) Refers to current object
D) Refers to static data

Q4: Which keyword is used to create a class in C++?

A) struct
B) class
C) object
D) type

Q5: Which C++ concept is used for code reuse?

A) Constructor
B) Abstraction
C) Inheritance
D) Encapsulation

Q6: What is the output of: cout << 5 / 2;

A) 2
B) 2.5
C) 2.0
D) Error

Q7: Which access specifier makes class members accessible only within the same class?

A) public
B) private
C) protected
D) internal

Q8: Which operator is overloaded for input in C++?

A) >>
B) <<
C) ==
D) ->

Q9: What does 'cin' represent in C++?

A) Console Input
B) Character Input
C) Class Input
D) Container Input

Q10: Which header file is needed for input/output stream?

A) conio.h
B) iostream
C) stdio.h
D) input.h

Q11: What is the keyword for defining a constant pointer?

A) constant
B) const
C) define
D) static

Q12: What is the role of a constructor in a class?

A) Free memory
B) Allocate memory
C) Initialize objects
D) Delete objects

Q13: What is the syntax to inherit a class in C++?

A) class A : inherits B
B) class A extends B
C) class A -> B
D) class A : public B

Q14: Which of the following is used to define a template?

A) generic
B) template
C) define
D) typename

Q15: Which container does not allow duplicate values in C++ STL?

A) vector
B) set
C) map
D) queue

Q16: Which of the following is used to create dynamic memory in C++?

A) malloc
B) calloc
C) new
D) create

Q17: What is the size of 'bool' data type in C++?

A) 1 byte
B) 2 bytes
C) 4 bytes
D) 8 bytes

Q18: What is function overloading?

A) Calling multiple functions
B) Using same function name with different parameters
C) Multiple return types
D) Nested functions

Q19: What is the output of: cout << true;

A) true
B) 1
C) 0
D) error

Q20: Which keyword is used to handle exceptions in C++?

A) exception
B) try
C) handle
D) error

Q21: Which block catches the thrown exception?

A) catch
B) try
C) throw
D) handle

Q22: How do you declare a pure virtual function?

A) virtual void func() = 0;
B) virtual func() = 1;
C) void virtual func();
D) virtual function();

Q23: What is a virtual function?

A) A static function
B) A function that can’t be overridden
C) A function overridden in derived class
D) A private function

Q24: Which operator cannot be overloaded?

A) ++
B) ==
C) .
D) ()

Q25: Which function is called when an object goes out of scope?

A) constructor
B) deleter
C) free
D) destructor

Q26: Which keyword is used to refer to base class method?

A) parent
B) base
C) super
D) scope resolution

Q27: What is the correct syntax to declare a reference variable?

A) int &a = b;
B) int *a = b;
C) ref int a = b;
D) int #a = b;

Q28: Which of the following supports LIFO?

A) queue
B) stack
C) list
D) set

Q29: Which header is used for vectors in C++?

A) array
B) vector
C) list
D) iostream

Q30: What is the output of: cout << sizeof(char);

A) 1
B) 2
C) 4
D) Depends

Q31: Which function is used to sort a vector?

A) sort()
B) order()
C) arrange()
D) reorder()

Q32: Which STL container uses key-value pairs?

A) vector
B) set
C) map
D) list

Q33: Which of the following is a smart pointer in C++?

A) shared_ptr
B) auto_ptr
C) unique_ptr
D) All of the above

Q34: What does 'namespace' do in C++?

A) Defines class
B) Avoids naming conflict
C) Declares variables
D) Manages memory

Q35: What is the default constructor?

A) Constructor with parameters
B) Constructor with no parameters
C) Copy constructor
D) Virtual constructor

Q36: Which operator is used to access members of a structure through a pointer?

A) .
B) ->
C) &
D) *

Q37: Which feature of C++ allows using the same name for different types?

A) Templates
B) Inheritance
C) Encapsulation
D) Overloading

Q38: Which function is used to release memory allocated by new?

A) delete
B) free
C) dispose
D) remove

Q39: What is the return type of main() in C++?

A) void
B) int
C) char
D) float

Q40: Which keyword prevents a variable from being changed?

A) final
B) constant
C) const
D) static

Q41: Which operator is used to compare two values?

A) =
B) ==
C) !=
D) <>

Q42: Which keyword creates an alias for a data type?

A) typedef
B) alias
C) using
D) both 1 and 3

Q43: Which type of inheritance involves one class derived from two base classes?

A) Single
B) Multilevel
C) Multiple
D) Hybrid

Q44: What is a friend function?

A) A function with no access
B) A private function
C) A function with access to private members
D) A child class function

Q45: What is the extension of header files in C++?

A) .head
B) .h
C) .cpp
D) .hpp

Q46: What happens if a constructor is private?

A) Cannot create object outside the class
B) Can’t inherit class
C) Error
D) Object auto-deletes

Q47: Which loop is best when number of iterations is known?

A) while
B) do...while
C) for
D) foreach

Q48: Which keyword is used to declare a static variable?

A) constant
B) static
C) fixed
D) persistent

Q49: What is the output of: cout << 'A' + 1;

A) A1
B) B
C) 66
D) Error

Q50: What happens if delete is used on non-dynamic memory?

A) Runtime error
B) Compile error
C) Undefined behavior
D) Segmentation fault