50 C Language MCQs with Answers

Question 1

C

#include <stdio.h>
// Assume base address of \"GeeksQuiz\" to be 1000
int main()
{
   printf(5 + \"GeeksQuiz\");
   return 0;
}

• GeeksQuiz
  

• Quiz
  

• 1005
  

• Compile-time error
  

Question 2

What does the following C statement mean? 

C

 scanf(\"%4s\", str);

• Read exactly 4 characters from console.
  

• Read maximum 4 characters from console.
  

• Read a string str in multiples of 4
  

• Nothing
  

Question 3

Consider the following ANSI C code segment: 

z=x + 3 + y->f1 + y->f2; 
for (i = 0; i < 200; i = i + 2) 
{ 
if (z > i) 
{ 
p = p + x + 3; 
q = q + y->f1; 
} else 
{ 
p = p + y->f2; 
q = q + x + 3; 
} 
} 
Assume that the variable y points to a struct (allocated on the heap) containing two fields f1 and f2, and the local variables x, y, z, p, q, and i are allotted registers. Common sub-expression elimination (CSE) optimization is applied on the code. The number of addition and the dereference operations (of the form y ->f1 or y ->f2) in the optimized code, respectively, are:

• 403 and 102
  

• 203 and 2
  

• 303 and 102
  

• 303 and 2
  

Question 4

Which of the following is true?

• gets() doesn\'t do any array bound testing and should not be used. 
  

• fgets() should be used in place of gets() only for files, otherwise gets() is fine
  

• gets() cannot read strings with spaces
  

• None of the above
  

Question 5

Predict the output?

C

int fun(char *str1){  char *str2 = str1;  while(*++str1);  return (str1-str2);}int main(){  char *str = \"GeeksQuiz\";  printf(\"%d\", fun(str));  return 0;}

• 10
  

• 9
  

• 8
  

• Random Number
  

Question 6

Given that x = 7.5, j = -1.0, n = 1.0, m = 2.0 the value of - - x + j == x>n> = m is: 

• 0
  

• 1
  

• 2
  

• 3
  

Question 7

If n has 3, then the statement a[++n]=n++;

• assigns 3 to a[5]
  

• assigns 4 to a[5]
  

• assigns 4 to a[4]
  

• what is assigned is compiler dependent
  

Question 8

#include "stdio.h"

int main() 

{ 

  int x, y = 5, z = 5; 

  x = y == z; 

  printf("%d", x); 

  

  getchar(); 

  return 0; 

}

• 0
  

• 1
  

• 5
  

• Compiler Error
  

Question 9

C

#include <stdio.h>
int main()
{
    int i = 3;
    printf(\"%d\", (++i)++);
    return 0;
}

What is the output of the above program?

• 3
  

• 4
  

• 5
  

• Compile-time error
  

Question 10

Which of the following is not a logical operator?

• && 
  

• ! 
  

• || 
  

• |