C Programming - Online Quiz

Answer : C

Explanation

No output, as we are comparing both base addresses and they are not same.

Q 2 - What is the output of the following program?

#include<stdio.h>

main()
{
   int i = 1;
   
   while(++i <= 5)
      printf("%d ",i++);
}

Answer : B

Explanation

2 4, at while first incremented and later compared and in printf printed first and incremented later

Q 3 - A macro can execute faster than a function.

A - true

B - false

Answer : A

Explanation

As the code of macro gets expanded at the line of call, therefore macro gets executed faster with no overhead of context switch.

Q 4 - What is the output of the following program?

#include<stdio.h>

main() 
{
   char *p = NULL;
   
   printf("%c", *p);
}

Answer : D

Explanation

It is invalid to access the NULL address hence giving run time error.

Q 5 - What is the output of the following statement?

#include<stdio.h>

main()
{
   printf("%d", -1<<1 );  
}

Answer : B

Explanation

A negative number stored in two’s compliment of positive number. After shifting we get 1110, which is equivalent to -2.

Q 6 - Which header statement is missing in the given below program to get the desired output?

#include<stdio.h>
#include<math.h>

int main ()
{
   double x = 1234321;
  
   double result = sqrt(x);
  
   printf("The square root of %.2lf is %.2lf\n", x, result);
   return 0;
}

A - #include<defs.h>

B - #include<math.h>

C - #include<stdlib.h>

D - Above program is absolutely correct to give desired result

Answer : B

Explanation

In C programming, math.h is a header file in the standard library designed for basic mathematical operations.

   Output of above code: The square root of 1234321.00 is 1111.00

#include<stdio.h>
#include<math.h>

int main ()
{
   double x = 1234321;
  
   double result = sqrt(x);
  
   printf("The square root of %.2lf is %.2lf\n", x, result);
   return 0;
}

Q 7 - Which of the following operator can be used to access value at address stored in a pointer variable?

Answer : A

Explanation

Pointer operator,

* (Value Operator) = Gives Value stored at Particular address

& (Address Operator) = Gives Address of Variable

Q 8 - Which of the following statement can be used to free the allocated memory?

A - remove(var-name);

B - free(var-name);

C - vanish(var-name);

D - erase(var-name);

Answer : B

Explanation

The library function free() deallocates the memory allocated by calloc(), malloc(), or realloc().

Q 9 - What will be the output of the following program?

#include<stdio.h>

int main()
{
   const int x = 5;
   
   const int *ptrx;
   ptrx = &x;
   *ptrx = 10;
   printf("%d\n", x);
   return 0;
}

A - 10

B - 20

C - 0

D - The program will return error

Answer : D

Explanation

The above program will return error

#include<stdio.h>

int main()
{
   const int x = 5;
   
   const int *ptrx;
   ptrx = &x;
   *ptrx = 10;
   printf("%d\n", x);
   return 0;
}

Q 10 - What will be the output of the given below code?

#include<stdio.h>

int main()
{
   const int *ptr = &i;
   
   char str[] = "Welcome";
   s = str;
   while(*s)
   printf("%c", *s++);
   return 0;
}

Answer : A

Explanation

Although, char str[] = "Welcome"; and s = str;, the program will print the value of s.

#include<stdio.h>

int main()
{
   const int *ptr = &i;
   
   char str[] = "Welcome";
   s = str;
   while(*s)
   printf("%c", *s++);
   return 0;
}