C (Programming Language) LinkedIn Skill Assessment Answer

Here, We see C (Programming Language) LinkedIn Skill Assessment Answers. This assessment test consists 15-20 MCQs to demonstrate your knowledge in your selected skills. MCQs comes from different topics.

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

1. ✔️

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");
}

1. ✔️

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

4. Nothing is printed on Screen

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

1. recursion✔️
2. subfunction
3. inner call
4. infinite loop

Q4. What does the declaration of variable c2 demonstrate?

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

1. character arithmetic✔️
2. undefined assignment
3. type conversion
4. 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;

1. f = _(float _)vptr;
2. f = (float *)vptr;
3. f = *(float *)vptr;✔️
4. f = *(float)vptr;

Q6. What is this declaration an example of?

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

1. a node✔️
2. a linked list
3. a stack
4. 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?

1. The preprocessor will try to locate the fileA in same directory as the source file, and the fileB in a predetermined directory path.
2. 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.
3. 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.
4. 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--;
}

4. ✔️

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?

1. volatile
2. typeof✔️
3. register
4. 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. 1✔️
2. 3
3. 2
4. 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;

1. 32
2. 54
3. 30✔️
4. 52

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

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

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

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

1. main()
2. int main() {return 0;}
3. main() { }✔️
4. main() { ; }

Q14. What is optional in a function declaration?

1. data type of parameters
2. return type of function
3. parameter names✔️
4. 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?

1. stdout✔️
2. stdio.h
3. default.h
4. string.h

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

1. BSS Segment
2. stack
3. heap✔️
4. data segment

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

1. dalloc()
2. dealloc()
3. release()
4. free()✔️

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

1. keywords
2. identifiers
3. tokens✔️
4. functions

Q19. When is memory for a variable allocated?

1. during the assigment of the variable
2. during the initialization of the variable
3. during the declaration of the variable✔️
4. 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?

1. by using pointers✔️
2. by declaring functions separately from defining them
3. by using recursive functions
4. by using global variables

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

1. Objects; Structure
2. Variables; Declaration
3. Data types; Memory location✔️
4. Arrays; Header file

Q22. What is the output of this program?

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

1. 32
2. Runtime error
3. -32✔️
4. 0

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

1. The scanf() function reads data formatted as a string; The sscanf() function reads string input from the screen.
2. The scanf() function reads formatted data from the keyboard; The sscanf() function reads formatted input from a string.✔️
3. The scanf() function reads string data from the keyboard; The sscanf() function reads string data from a string.
4. 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"};

1. printf(“%c”, string[1][2]);
2. printf(“%s”, string[1][2]);✔️
3. printf(“%s”, string[1]);
4. printf(string[1]);

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

1. player.name
2. (*player).name✔️
3. *player.name
4. player.*name

Q26. Which program will compile and run without errors?

main() {
    for(i=0; i<10; i++) ;
}

2. ✔️

main() {
int i=0;
    for(; i<10; i++) ;
}

main() {
    int i;
    for(i=0; i<j; i++) ;
}

main() {
int i;
    for (i= 10; i<10; i++)
}

Q27. What does this function call return?

1 main() { float x = f1(10, 5); }
2 float f1(int a, int b) { return (a/b); }

1. 2
2. 2.000000
3. a runtime error
4. a compiler error✔️

Q28. What does this program create?

#include <stdio.h>
int main() {
    int *p = NULL;
    return 0;
}

1. a runtime error
2. a NULL pointer✔️
3. a compile error
4. a void pointer

Q29. What is an alternative way to write the expression (*x).y?

1. There is no equivalent.
2. x->y✔️
3. *x->y
4. y->x

Q30. Compile time errors are static errors that can be found where in the code?

1. in declarations and definitions✔️
2. in functions and expressions
3. in syntax and semantics
4. in objects and statements

Q31. File input and output (I/O) in C is heavily based on the way it is done ___?

1. in Unix✔️
2. in C++
3. in C#
4. in DOS

Q32. What does the strcmp(str1, str2); function return?

1. 0 if str1 and str2 are the same, a negative number if str1 is less than str2, a positive number if str1 is greater than str2✔️
2. true (1) if str1 and str2 are the same, false (0) if str1 and str2 are not the same
3. true (1) if str1 and str2 are the same, NULL if str1 and str2 are not the same
4. 0 if str1 and str2 are the same, a negative number if str2 is less than str1, a positive number if str2 is greater than str1

Q33. What is the output of this program?

int a=10, b=20;
int f1(a) { return(a*b); }
main() {
printf("%d", f1(5));
}

1. 100✔️
2. 200
3. 5
4. 50

Q34. Which is not a correct way to declare a string variable?

1. char *string = “Hello World”;
2. char string = “Hello World”;✔️
3. char string[20] = {‘H’, ‘e’, ‘l’, ‘l’, ‘o’, ‘ ‘, ‘W’, ‘o’, ‘r’, ‘l’, ‘d’};
4. char string[] = “Hello World”;

Q35. Which choice is an include guard for the header file mylib.h?

#ifdef MYLIB_H
#undef MYLIB_H

// mylib.h content

#endif /* MYLIB_H */

2. ✔️

#ifndef MYLIB_H
#define MYLIB_H

// mylib.h content

#endif /* MYLIB_H */

#define MYLIB_H
#include "mylib.h"

#undef MYLIB_H

#ifdef MYLIB_H
#define MYLIB_H

// mylib.h content

#endif /* MYLIB_H */

Q36. How many times does the code inside the while loop get executed in this program?

main(){
 int x=1;
 while(x++<100){
    x*=x;
    if(x<10) continue;
    if(x>50) break
 }
}

1. 100
2. 3✔️
3. 5
4. 50

Q37. File input and output (I/O) in C is done through what?

1. syntax-driven components
2. native interfaces
3. system objects
4. function calls✔️

Q38. Directives are translated by the?

1. Pre-processor✔️
2. Compiler
3. Linker
4. Editor