Virtual Functions MCQs in Object Oriented Programming Part 1. This set of mcqs contains Virtual Functions in oop for competitive exams, SPPU online exams 2020.
1 What does the following statement mean?
int (*fp)(char*)
A pointer to a pointer
B pointer to an array of chars
C pointer to function taking a char* argument and returns an int
D function taking a char* argument and returning a pointer to int
Answer C
2 The operator used for dereferencing or indirection is ____
A *
B &
C ->
D –>>
Answer A
3 Choose the right option
string* x, y;
A x is a pointer to a string, y is a string
B y is a pointer to a string, x is a string
C both x and y are pointer to string types
D none of the mentioned
Answer A
4 Which one of the following is not a possible state for a pointer?
A hold the address of the specific object
B point one past the end of an object
C Zero
D point to a byte
Answer D
5 Which of the following is illegal?
A int *ip;
B string s, *sp = 0;
C int i; double* dp = &i;
D int *pi = 0;
Answer D
6 #include <iostream>
using namespace std;
int main()
{
int a = 5, b = 10, c = 15;
int *arr[ ] = {&a, &b, &c};
cout <<arr[1];
return 0;
}
A 10
B 15
C 20
D Random number
Answer D
7 The correct statement for a function that takes pointer to a float, a pointer to a pointer to a
char and returns a pointer to a pointer to a integer is
A int **fun(float**, char**)
B int *fun(float*, char*)
C int ***fun(float*, char**)
D int ***fun(*float, **char)
Answer C
8 #include <iostream>
using namespace std;
int main()
{
char arr[20];
int i;
for(i = 0; i < 10; i++)
*(arr + i) = 65 + i;
*(arr + i) = '\0';
cout << arr;
return(0);
}
A ABCDEFGHIJ
B AAAAAAAAA
C JJJJJJJJJJJJ
D None
Answer A
9 #include <iostream>
using namespace std;
int main()
{
char *ptr;
char Str[] = "abcdefg";
ptr = Str;
ptr += 5;
cout << ptr;
return 0;
}
A fg
B cdef
C defg
D abcd
Answer A
10 Which rule will not affect the friend function?
A private and protected members of a class cannot be accessed from outside
B private and protected member can be accessed anywhere
C both a &b
D None
Answer A
11 Which keyword is used to declare the friend function?
A Firend
B friend
C Classfriend
D myfriend
Answer B
12 #include <iostream>
using namespace std;
class Box
{
double width;
public:
friend void printWidth( Box box );
void setWidth( double wid );
};
void Box::setWidth( double wid )
{
width = wid;
}
void printWidth( Box box )
{
box.width = box.width * 2;
cout << "Width of box : " << box.width << endl;
}
int main( )
{
Box box;
box.setWidth(10.0);
printWidth( box );
return 0;
}
A 40
B 5
C 10
D 20
Answer D
13 Pick out the correct statement.
A A friend function may be a member of another class.
B A friend function may not be a member of another class.
C A friend function may or may not be a member of another class.
D None of the mentioned
Answer C
14 Where does keyword „friend‟ should be placed?
A function declaration
B function definition
C main function
D None
Answer A
15 #include <iostream>
using namespace std;
class sample
{
private:
int a, b;
public:
void test()
{
a = 100;
b = 200;
}
friend int compute(sample e1);
};
int compute(sample e1)
{
return int(e1.a + e1.b) - 5;
}
int main()
{
sample e;
e.test();
cout << compute(e);
return 0;
}
A 100
B 200
C 300
D 295
Answer D
16 #include <iostream>
using namespace std;
class base
{
int val1, val2;
public:
int get()
{
val1 = 100;
val2 = 300;
}
friend float mean(base ob);
};
float mean(base ob)
{
return float(ob.val1 + ob.val2) / 2;
}
int main()
{
base obj;
obj.get();
cout << mean(obj);
return 0;
}
A 200
B 150
C 100
D 300
Answer A
17 To which does the function pointer point to?
A Variable
B Constants
C Function
D absolute variables
Answer C
18 What we will not do with function pointers?
A allocation of memory
B de-allocation of memory
C both a &b
D None
Answer C
19 #include <iostream>
using namespace std;
int add(int first, int second)
{
return first + second + 15;
}
int operation(int first, int second, int (*functocall)(int, int))
{
return (*functocall)(first, second);
}
int main()
{
int a;
int (*plus)(int, int) = add;
a = operation(15, 10, plus);
cout << a;
return 0;
}
A 25
B 36
C 40
D 45
Answer C
20 #include <iostream>
using namespace std;
void func(int x)
{
cout << x ;
}
int main()
{
void (*n)(int);
n = &func;
(*n)( 2 );
n( 2 );
return 0;
}
A 2
B 21
C 22
D 20
Answer C
21 #include <iostream>
using namespace std;
int n(char, int);
int (*p) (char, int) = n;
int main()
{
(*p)('d', 9);
p(10, 9);
return 0;
}
int n(char c, int i)
{
cout << c << i;
return 0;
}
A d9
9
B d9d9
C d9
D Compile time error
Answer A
22 #include <iostream>
using namespace std;
int func (int a, int b)
{
cout << a;
cout << b;
return 0;
}
int main(void)
{
int(*ptr)(char, int);
ptr = func;
func(2, 3);
ptr(2, 3);
return 0;
}
A 2323
B 232
C 23
D Compile time error
Answer D
23 What are the mandatory part to present in function pointers?
A &
B return values
C Data types
D None
Answer C
24 What is meaning of following declaration?
int(*ptr[5])();
A ptr is pointer to function.
B ptr is array of pointer to function.
C ptr is pointer to such function which return type is array.
D ptr is pointer to array of function.
Answer B
25 What is size of generic pointer in c?
A 0
B 1
C 2
D Null
Answer C
26 Void pointer can point to which type of objects?
A Int
B Float
C Double
D All
Answer D
27 What does the following statement mean?
int (*fp)(char*)
A pointer to a pointer
B pointer to an array of chars
C pointer to function taking a char* argument and returns an int
D function taking a char* argument and returning a pointer to int
Answer C
28 What is size of generic pointer in C++ (in 32-bit platform) ?
A 2
B 4
C 8
D 0
Answer B
29 #include <iostream>
using namespace std;
int main()
{
int a[2][4] = {3, 6, 9, 12, 15, 18, 21, 24};
cout << *(a[1] + 2) << *(*(a + 1) + 2) << 2[1[a]];
return 0;
}
A 15 18 21
B 21 21 21
C 24 24 24
D Compile time error
Answer B
30 #include <iostream>
using namespace std;
int main()
{
int i;
char *arr[] = {"C", "C++", "Java", "VBA"};
char *(*ptr)[4] = &arr;
cout << ++(*ptr)[2];
return 0;
}
A ava
B java
C c++
D Compile time error
Answer A
