Integer Types(C++ Programming ) Questions and answers for exam Preparation

Question 1.

What will be output of this function?

1.
int main()
2.
{
3.
register int i = 1;
4.
int *ptr = &i;
5.
cout

0
1
Compiler error may be possible
Runtime error may be possible

Explanation:-

Answer: Option C. -> Compiler error may be possible

Using & on a register variable may be invalid, since the compiler may store the variable in a register, and

finding the address of it is illegal.

Question 2.

What will be output of this program?

1.
#include
2.
using namespace std;
3.
int main()
4.
{
5.
int i = 3;
6.
int l = i / -2;
7.
int k = i % -2;
8.
cout

compile time error
-1 1
1 -1
implementation defined

Explanation:-

Answer: Option B. -> -1 1

Sign of result of mod operation on negative numbers is sign of the dividend.

Question 3.

What will be the output of this program?

1.
#include
2.
using namespace std;
3.
int main()
4.
{
5.
int a = 8;
6.
cout << "ANDing integer 'a' with 'true' :"" << a && true;
7.
return 0;
8.
}

integer 'a' with 'true' :8
ANDing integer 'a' with 'true' :0
ANDing integer 'a' with 'true' :1
None of the mentioned

Explanation:-

Answer: Option A. -> integer 'a' with 'true' :8

None.

Question 4.

0946, 786427373824, 'x' and 0X2f are _____, _____, ____ and _____ literals respectively

decimal, character,octal, hexadecimal
octal, hexadecimal, character, decimal
hexadecimal, octal, decimal, character
octal, decimal, character, hexadecimal

Explanation:-

Answer: Option D. -> octal, decimal, character, hexadecimal

Literal integer constants that begin with 0x or 0X are interpreted as hexadecimal and the ones that begin

with 0 as octal. The character literal are written within ".

Question 5.

Which of these expressions will isolate the rightmost set bit?

x = x & (~x)
x = x ^ (~x)
x = x & (-x)
x = x ^ (-x)

Explanation:-

Answer: Option C. -> x = x & (-x)

None.

Question 6.

Which of these expressions will make the rightmost set bit zero in an input integer x?

x = x | (x-1)
x = x & (x-1)
x = x | (x+1)
x = x & (x+1)

Explanation:-

Answer: Option B. -> x = x & (x-1)

None.

Question 7.

Which of these expressions will return true if the input integer v is a power of two?

(v | (v + 1)) == 0;
(~v & (v - 1)) == 0;
(v | (v - 1)) == 0;
(v & (v - 1)) == 0;

Explanation:-

Answer: Option D. -> (v & (v - 1)) == 0;

Power of two integers have a single set bit followed by unset bits.

Question 8.

What is the value of the following 8-bit integer after all statements are executed?
int x = 1;
x = x << 7;
x = x >> 7;

1
-1
127
Implementation defined

Explanation:-

Answer: Option D. -> Implementation defined

Right shift of signed integers is undefined, and has implementation-defined behaviour.

Question 9.

The size_t integer type in C++ is?

Unsigned integer of at least 64 bits
Signed integer of at least 16 bits
Unsigned integer of at least 16 bits
Signed integer of at least 64 bits

Explanation:-

Answer: Option C. -> Unsigned integer of at least 16 bits

The size_t type is used to represent the size of an object. Hence, itâ€™s always unsigned. According to

the language specification, it is at least 16 bits.

Question 10.

What is the output of the following program?

1.
#include
2.
using namespace std;
3.
int main()
4.
{
5.
int x = -1;
6.
unsigned int y = 2;
7.
8.
if(x > y) {
9.
cout

x is greater
y is greater
Implementation defined
Arbitrary

Explanation:-

Answer: Option A. -> x is greater

x is promoted to unsigned int on comparison. On conversion x has all bits set, making it the bigger one.