Questions and answers for exam Preparation

MCQs

Total Questions : 64 | Page 6 of 7 pages

What will be output of following program?

#include<stdio.h>
#include<string.h>
int main()
{
int register a;
scanf("%d",&a); // say a = 10
printf("%d",a);
return 0;
}

10
Address
0
Compilation error
None of the above

Discuss Question

Answer: Option D. -> Compilation error

Question 52.
What will be the output of the following program :
#include<stdio.h>
main()
{
int val=1234;
int* ptr=&val;
printf("%d %d",val,*ptr++);
}

1234 1234
1235 1235
1234 1235
1235 1234

Discuss Question

Answer: Option A. -> 1234 1234

Question 53.
What will be the output of the following program :
#include<stdio.h>
main()
{
int val=1234;
int* ptr=&val;
printf("%d %d",++val,(*(int *)ptr)--);
}

1234 1233
1235 1234
1234 1234
None of these

Discuss Question

Answer: Option C. -> 1234 1234

Question 54.

What will be output of following program?

#include<stdio.h>
#include<string.h>
int main()
{
int a,b,c,d;
char *p = (char*)0;
int *q = (int*q)0;
float *r = (float*)0;
double *s = 0;
a = ( int)(p+1);
b = ( int)(q+1);
c = ( int)(r+1);
d = ( int)(s+1);
printf("%d %d %d %d",a,b,c,d);
return 0;
}

2 2 2 2
1 2 4 8
1 2 2 4
Compilation error
None of the above

Discuss Question

Answer: Option B. -> 1 2 4 8

Address + 1 = next address

Question 55.

In which header file is the NULL macro defined?

stdio.h
stddef.h
stdio.h and stddef.h
math.h

Discuss Question

Answer: Option C. -> stdio.h and stddef.h

The macro "NULL" is defined in locale.h, stddef.h, stdio.h, stdlib.h, string.h, time.h, and wchar.h.

Question 56.
What will be the output of the following program :
#include<stdio.h>
main()
{
int val=1234;
int* ptr=&val;
printf("%d %d",++val,*ptr);
}

1234 1234
1235 1235
1234 1235
1235 1234

Discuss Question

Answer: Option D. -> 1235 1234

Question 57.
What will be the output of the following program :
#include<stdio.h>
main()
{
int a=555,*ptr=&a,b=*ptr=777;
printf("%d %d",--*&b,*(int *)&b);
}

Compile Error
776 777
554 555
None of these

Discuss Question

Answer: Option B. -> 776 777

Question 58.

What will be output of following program?

#include<stdio.h>
int main()
{
int i = 5;
int *p;
p = &i;
printf("%u %u",*&p, &*p);
return 0;
}

5 Address
Address Address
Address 5
Compilation error
None of the above

Discuss Question

Answer: Option B. -> Address Address

Since * and & always cancel to each other.

i.e. *&a = a

so *&p = p which store address of integer i

&*p = &*(&i) //since p = &i

= &(*&i)

= &i

So second output is also address of i

Question 59.
What will be the output of the following program :
#include<stdio.h>
main()
{
int a=555,*ptr=&a,b=*ptr;
printf("%d %d %d",++a,--b,*ptr++);
}

Compile error
555 554 555
556 554 555
557 554 555

Discuss Question

Answer: Option C. -> 556 554 555

Question 60.
What will be the output of the following program :
#include<stdio.h>
main()
{
int val=1234;
int* ptr=&val;
printf("%d %d",val,++*ptr);
}