C++ Programming Questions and Answers – Pointer to Void

Q 1. The void pointer can point to which type of objects?
A. int
B. float
C. double
D. all of the mentioned

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Answer:-B. float

Explanation

Because it doesn’t know the type of object it is pointing to, So it can point to all objects.

Q 2. When does the void pointer can be dereferenced?
A. when it doesn’t point to any value
B. when it cast to another type of object
C. using delete keyword
D. using shift keyword

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Answer:-B. when it cast to another type of object

Explanation

By casting the pointer to another data type, it can be dereferenced from the void pointer.

Q 3. The pointer can point to any variable that is not declared with which of these?
A. const
B. volatile
C. static
D. both const & volatile

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Answer:-D. both const & volatile

Explanation

Pointer can point to any variable that is not declared with const & volatile.

Q 4. A void pointer cannot point to which of these?
A. methods in c++
B. class member in c++
C. methods & class member in c++
D. none of the mentioned

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Answer:-D. none of the mentioned

Explanation

A void pointer can point to methods & class member in c++.

Q 5. What will be the output of the following C++ code?

#include <iostream>

using namespace std;

int func(void *Ptr);

int main()

{

char *Str = “abcdefghij”;

func(Str);

return 0;

}

int func(void *Ptr)

{

cout << Ptr;

return 0;

}

A. abcdefghij
B. address of string “abcdefghij”
C. compile time error
D. runtime error

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Answer:-B. address of string “abcdefghij”

Explanation

Even though it is a void pointer, we gets the address. Output: $ g++ b.cpp $ a.out 0x8048714

Q 6. What will be the output of the following C++ code?

#include <iostream>

using namespace std;

int main()

{

int *p;

void *vp;

if (vp == p)

cout << “equal”;

return 0;

}

A. no output
B. equal
C. compile error
D. runtime error

Show Answer

Answer:-B. equal

Explanation

The void pointer is easily converted to any other type of pointer, so these are equal. Output: $ g++ poi4.cpp $ a.out equal

Q 7. What will be the output of the following C++ code?

#include <iostream>

using namespace std;

int main()

{

int i;

char c;

void *data;

i = 2;

c = ‘d’;

data = &i;

cout << “the data points to the integer value” << data;

data = &c;

cout << “the data now points to the character” << data;

return 0;

}

A. 2d
B. 3d
C. 4d
D. two memory addresses

Show Answer

Answer:-D. two memory addresses

Explanation

Because the data points to the address value of the variables only, So it is printing the memory address of these two variable. Output: $ g++ poi2.cpp $ a.out the data points to the integer value0xbfc81824 the data now points to the character0xbfc8182f

Q 8. What will be the output of the following C++ code?

#include <iostream>

using namespace std;

int main()

{

int n = 5;

void *p = &n;

int *pi = static_cast<int*>(p);

cout << *pi << endl;

return 0;

}

A. 5
B. 6
C. compile time error
D. runtime error

Show Answer

Answer:-A. 5

Explanation

We just casted this from void to int, so it prints 5 Output: $ g++ poi1.cpp $ a.out 5

Q 9. What will be the output of the following C++ code?

#include <iostream>

using namespace std;

int main()

{

int a = 5, c;

void *p = &a;

double b = 3.14;

p = &b;

c = a + b;

cout << c << ‘\n‘ << p;

return 0;

}

A. 8, memory address
B. 8.14
C. memory address
D. 12

Show Answer

Answer:-A. 8, memory address

Explanation

In this program, we are just adding the two values and printing it. Output: $ g++ poi.cpp $ a.out 8 0xbfef0378

Q 10. What we can’t do on a void pointer?
A. pointer functions
B. pointer arithmetic
C. pointer objects
D. pointer functions & objects

Show Answer

Answer:-B. pointer arithmetic

Explanation

Because the void pointer is used to cast the variables only, So pointer arithmetic can’t be done in a void pointer.