c-quiz.md

C (Programming Language)

Q1. Which Code saple will eventually cause the computer to run out of memory ?

• while(1)
  {
      char *smallString = (char *) malloc(10);
  }

• long long number = 1;
  while(1)
      number *= 2;

• while(1)
  {
      char hugeString[1000000L];
      memset(hugeString, 0, 1000000L);
  }

• while(1)
  {
      long *bigArray = (long *) malloc(sizeof(long) * 1000);
      memset(bigArray, 1000000, 1000);
      free(bigArray);
  }

Q2. What will this code print on the screen?

int f1 (int a, int b)
{
    if (a > b)
    {
        printf("A is greater than B\n");
        return 1;
    }
    else
    {
        printf("B is greater than A");
        return 0;
    }
}

main()
{
    if (f1(20,10) || f1(10,20))
        printf("C is fun!\n");
}

• A is greater then B C is fun!

• A is greater then B B is greater then A C is fun!

• A is greater then B B is greater then A

• Northing is printed on Screen

Q3. What is the name for calling a function inside the same function?

• recursion
• subfunction
• inner call
• infinite loop

Q4. What does the declaration of variable c2 demonstrate?

main(){
    char c1 ='a';
    char c2 = c1+10;
}

• character arithmetic
• undefined assignment
• type conversion
• invalid declaration

Q5. A pointer to void named vptr, has been set to point to a floating point variable named g. What is the valid way to dereference vptr to assign its pointed value to a float variable named f later in this program?

float g;
void *vptr=&g;

• f = _(float _)vptr;
• f = (float *)vptr;
• f = (float)*vptr;
• f = *(float)vptr;

Q6. What is this declaration an example of?

struct s {
    int i;
    struct s *s1;
    struct s *s2;
};

• a node
• a linked list
• a stack
• a binary tree

Q7. A C header file is a file with extension .h that contains function declarations and macro definitons to be shared between several source files. Header files are listed using the preprocessing directive #include, and can have one of the following formats: #include <fileA> or #include "fileB". What is the difference between these two formats?

• The preprocessor will try to locate the fileA in same directory as the source file, and the fileB in a predetermined directory path.
• The preprocessor will try to locate the fileA in the fixed system directory. It will try to locate fileB in the directory path designated by the -l option added to the command line while compiling the source code.
• The file using fileA syntax must be system files, of unlimited number. fileB must be a user file at a maximun of one per source file.
• The preprocessor will try to locate the fileA in a predetermined directory path. It will try to locate fileB in the same directory as the source file along with a custom directory path.

Q8. Using a for loop, how could you write a C code to count down from 10 to 1 and display each number on its own line?

• for (int i = 0; i>=0, i--){
      printf("%d\n", i);
  }//end of loop

• int i;
  for (i=1; i<=10; i++){
      printf("%d", i);
  }

• int i = 10;
  while (i>0){
      printf("%d\n", i);
      i--;
  }

• int i;
  for (i= 10; i>0; i--){
      printf("%d\n", i);
  }// end of loop

Q9. What is not one of the reserved words in standard C?

• volatile
• typeof
• register
• typedef

Q10. What does the program shown below return?

int main(){
    int a=1, b=2, c=3, d=4;
    int x = a;
    if (a>b)
    if (b<c) x=b;
    else x=c;
    return(x);
}

• 1
• 3
• 2
• 0

Q11. Using the Union declaration below, how many bytes of memory space will the data of this type occupy?

union Cars{
    char make[20];
    char model[30];
    short year;
}car;

• 32
• 54
• 30
• 52

Q12. In this code sample, what is not a problem for C compiler?

main(){
    constant int PI = 3.14;
    printf("%f\n", pi);
}

• The value of PI needs to be set to 3.141593, not 3.14
• The declaration of PI needs to say const, not constant.
• The data type of PI needs to be float not int.
• The printf statement needs to use PI, not pi.

Q13. Which is the smallest program to compile and run without errors?

• main()
• int main() {return 0;}
• main() { }
• main() { ; }

Q14. What is optional in a function declaration?

• data type of parameters
• return type of function
• parameter names
• number of parameters

Q15. C treats all devices, such as the display and the keyboard, as files. Which files opens automatically when a program executes?

• stdout
• stdio.h
• default.h
• string.h

Q16. In which segment does dynamic memory allocation takes place?

• BSS Segment
• stack
• heap
• data segment

Q17. Which of the following do you use to deallocate memory?

• dalloc()
• dealloc()
• release()
• free()

Q18. In C language what are the basic building blocks that are constructed together to write a program?

• keywords
• identifiers
• tokens
• functions

Q19. When is memory for a variable allocated?

• during the assigment of the variable
• during the initialization of the variable
• during the declaration of the variable
• during the definition of the variable

Q20. By default c uses the call by value method to pass arguments to functions. How can you invoke the call by reference method?

• by using pointers
• by declaring functions separately from defining them
• by using recursive functions
• by using global variables

Q21. A union allows you to store different _ in the same _.

• Objects; Structure
• Variables; Declaration
• Data types; Memory location
• Arrays; Header file

Q22. What is the output of this program?

main(){
    char c1='a' , c2='A';
    int i=c2-c1;
    printf("%d", i);
}

• 32
• Runtime error
• -32
• 0

Q23. What is the difference between scanf() and sscanf() functions?

• The scanf() function reads data formatted as a string; The sscanf() function reads string input from the screen.
• The scanf() function reads formatted data from the keyword; The sscanf() function reads formatted input from a string.
• The scanf() function reads string data from the keyword; The sscanf() function reads string data from a string.
• The scanf() function reads formatted data from a file; The sscanf() function reads input from a selected string

Q24. What is not a valid command with this declaration?

char *string[20] = { "one", "two", "three"};

• printf("%c", string[1][2]);
• printf("%s", string[1][2]);
• printf("%s", string[1]);
• printf(string[1]);

Q25. What is the expression player->name equivalent to?

• player.name
• (*player).name
• *player.name
• player.*name