C Question Set 1-3

Tech Index 1 2 3 4 5 6 7

Question 1

What  restrictions apply to reference variables?



You cannot  reference a reference variable (i.e. you cannot take its address)

You cannot  create arrays of references

References are  not allowed on bit fields

All of the  above



Question 2

What is the  output of the program?



#include  <iostream.h>

struct Emp

{

int id;

float basic;

float  cal_salary();

void  show_emp();

};

void main()

{

Emp e1;

e1.basic =  5000.5;

cout <<  e1.basic <<endl;

}



5000

5000.5

Error - as  private data cannot be accessed

None of the  above



Question 3

What is the  output of the program?



#include  <iostream.h>

class test

{

test()

{

cout <<  "constructor called" ;

}

};



void main()

{

test a();

}



constructor  called

Error -  constructor cannot be private

no output is  displayed

None of the  above





Question 4

What is the  output of the program?

#include  <iostream.h>

class test

{

int x;

public:

test(int y)

{

x = y;

}



int getX()

{

int x = 40;

return  this->x;

}

};



void main()

{

test a(10);

cout <<  a.getX();

}

Compilation  error

10

40

None of the  above



Question 5

What is the  prototype of pre increment operator in class test?



void operator  ++ ();

test operator  ++ (int);

void operator  ++ (int);

test operator  ++ ();



Question 6

What  restrictions apply to extern "C"?



You can  specify extern "C" for only one instance of an overloaded function;  all other instances of an overloaded function have C++ linkage

You can only  declare C functions as 'extern "C"

You cannot  declare a member function with extern "C"

Both A and C



Question 7

What is the  output of the program?



#include  <iostream.h>



void fun(int  & a, int b)

{

a += 20;

b += 30;

}



void main()

{

int x = 10, y  = 50;

fun(x, y);

cout <<  x << " " << y ;

}



30 80

10 50

30 50

10 80



Question 8

What is the  output of the following?

#include  <iostream.h>

class test

{

char x;

static char c;

};

void main()

{

test a;

cout <<  sizeof(a);

}



1

2

4

None of the  above

Question 9

What is the  signature of the output operator for class test?

friend ostream  & operator << (test &);

ostream &  operator << (test &);

ostream &  operator << (ostream &, test &);

friend ostream  & operator << (ostream &, test &);



Question 10

What is the  member function called in the statement "test b = a" shown below?

void main()

{

test a(10);

test b = a;

}



Assignment  operator

Constructor

Copy  constructor

None of the  above



Question 11

A variable  that is part of a class, yet is not part of an object of that class, is called  a?



Static member

Friend member

Constant  member

Non-static  member



Question 12

The only  member functions that could be called for const objects would be?

Constructors

Destructor

Const member  functions

All of the  above



Question 13

Which of the  following type conversions is automatic?



Conversion  from built-in type to class type

Conversion  from class type to built-in type

Conversion  from one class type to another class type

None of the  above



Question 14

Which keyword  do we use if the data members of the class are to be modified even when it  belongs to a constant object?



mutable

static

const

friend



Question 15

Which  condition should the conversion function from class type to built-in type  satisfy?



It must be a  class member

It must not  specify a return type

It must not  have any arguments

All of the  above

Question 16

We prefer  initialization to assignment for the following reason?



Const members  can only be initialized

Reference  members can only be initialized

To improve the  efficiency, when a class contains a data member which is an object of another  class

All of the  above

Question 17

Which keyword  specifies that those members are accessible only from member functions and  friends of the class and its derived classes?



private

public

protected

All of the  above



Question 18

Which of the  following statements is correct?



When preceding  the name of a base class, the protected keyword specifies that the public and  protected members of the base class are protected members of the derived class

Default access  of a base class is private for classes

Default access  of a base class is public for structures

All of the  above



Question 19

What is the  output of the program?

# include  <iostream.h>

union test {

int x;

};

class uc :  public test

{

int y;

};

main()

{

uc u;

cout <<  sizeof(u);

}

8

4

union cannot  be used as base class

None of the  above



Question 20

Which of the  following statements are true about static member functions?

Cannot make  use of this pointer

Cannot access  any non-static data

Cannot be  declared const

All of the  above



Answers

Answer 1 - D

Answer 2 - B

Answer 3 - C

Answer 4 - B

Answer 5 - D

Answer 6 - D

Answer 7 - C

Answer 8 - A

Answer 9 - D

Answer 10 - C

Answer 11 - A

Answer 12 - D

Answer 13 - D

Answer 14 - A

Answer 15 - D

Answer 16 - D

Answer 17 - C

Answer 18 - D

Answer 19 - C

Answer 20 - D