Declarations - C Multiple Choice Questions and Answers

1. What is the output of this C code?

void foo(const int *);
int main()
{
const int i = 10;
printf("%d ", i);
foo(&i);
printf("%d", i);
}
void foo(const int *i)
{
*i = 20;
}

• A. Compile time error
• B. 10    20
• C. Undefined value
• D. 10
• 2. Comment on the output of this C code?
  
  int main()
  {
  const int i = 10;
  int *ptr = &i;
  *ptr = 20;
  printf("%d\n", i);
  return 0;
  }
  • A. Compile time error
  • B. Compile time warning and printf displays 20
  • C. Undefined behaviour
  • D. 10
  • 3. What is the output of this C code?
    
    int main()
    {
    j = 10;
    printf("%d\n", j++);
    return 0;
    }

    • A. 10
    • B. 11
    • C. Compile time error
    • D. 0

    
    
    4. Does this compile without error?
    
    int main()
    {
    for (int k = 0; k < 10; k++);
    return 0;
    }

    • A. Yes
    • B. No
    • C. Depends on the C standard implemented by compilers
    • D. None of the mentioned

    
    
    5. Does this compile without error?
    
    int main()
    {
    int k;
    {
    int k;
    for (k = 0; k < 10; k++);
    }
    }

    • A. Yes
    • B. No
    • C. Depends on the compiler
    • D. Depends on the C standard implemented by compilers
    • 6. Which of the following declaration is not supported by C?
      • A. String str;
      • B. char *str;
      • C. float str = 3e2;
      • D. Both (a) and (c)
      • 7. Which of the following format identifier can never be used for the variable var?
        
        int main()
        {
        char *var = "Advanced Training in C by AllIndiaExams.com";
        }
        • A. %f
        • B. %d
        • C. %c
        • D. %s
        • 8. Which of the following declaration is illegal?
          • A. char *str = “Best C programming classes by AllIndiaExams”;
          • B. char str[] = “Best C programming classes by AllIndiaExams”;
          • C. char str[20] = “Best C programming classes by AllIndiaExams”;
          • D. char[] str = “Best C programming classes by AllIndiaExams”;
          • 9. Which keyword is used to prevent any changes in the variable within a C program?
            • A. immutable
            • B. mutable
            • C. const
            • D. volatile
            • 10. Which of the following is not a pointer declaration?
              • A. char a[10];
              • B. char a[] = {’1', ’2', ’3', ’4'};
              • C. char *str;
              • D. char a;
            •