- C Programming Tutorial
- C - Home
- C - Overview
- C - Environment Setup
- C - Program Structure
- C - Basic Syntax
- C - Data Types
- C - Variables
- C - Constants
- C - Storage Classes
- C - Operators
- C - Decision Making
- C - Loops
- C - Functions
- C - Scope Rules
- C - Arrays
- C - Pointers
- C - Strings
- C - Structures
- C - Unions
- C - Bit Fields
- C - Typedef
- C - Input & Output
- C - File I/O
- C - Preprocessors
- C - Header Files
- C - Type Casting
- C - Error Handling
- C - Recursion
- C - Variable Arguments
- C - Memory Management
- C - Command Line Arguments
- C Programming useful Resources
- C - Questions & Answers
- C - Quick Guide
- C - Useful Resources
- C - Discussion
- Selected Reading
- UPSC IAS Exams Notes
- Developer's Best Practices
- Questions and Answers
- Effective Resume Writing
- HR Interview Questions
- Computer Glossary
- Who is Who
C Programming Mock Test
This section presents you various set of Mock Tests related to C Programming Framework. You can download these sample mock tests at your local machine and solve offline at your convenience. Every mock test is supplied with a mock test key to let you verify the final score and grade yourself.
C Programming Mock Test I
Q 1 - What is the output of the following code snippet?
#include<stdio.h>
main()
{
int const a = 5;
a++;
printf(“%d”,a);
}
Answer : D
Explanation
Compile error - constant variable cannot be modified.
main()
{
int const a = 5;
a++;
printf(“%d”,a);
}
Q 2 - What is the output of the following code snippet?
#include<stdio.h>
main()
{
const int a = 5;
a++;
printf("%d", a);
}
Answer : D
Explanation
Compile error - constant variable cannot be modified.
main()
{
const int a = 5;
a++;
printf("%d", a);
}
Q 3 - What is the output of the below code snippet?
#include<stdio.h>
main()
{
char s[]="hello", t[]="hello";
if(s==t){
printf("eqaul strings");
}
}
Answer : C
Explanation
No output, as we are comparing both base addresses and they are not same.
Q 4 - What is the output of the below code snippet?
#include<stdio.h>
main()
{
int a = 5, b = 3, c = 4;
printf("a = %d, b = %d\n", a, b, c);
}
Answer : A
Explanation
a=5,b=3 , as there are only two format specifiers for printing.
Q 5 - What is the output of the below code snippet?
#include<stdio.h>
main()
{
int a = 1;
float b = 1.3;
double c;
c = a + b;
printf("%.2lf", c);
}
Answer : A
Explanation
2.30, addition is valid and after decimal with is specified for 2 places.
Q 6 - What is the outpout of the following program?
#include<stdio.h>
main()
{
enum { india, is=7, GREAT };
printf("%d %d", india, GREAT);
}
Answer : C
Explanation
0 8, enums gives the sequence starting with 0. If assigned with a value the sequence continues from the assigned value.
Q 7 - What is the output of the following code snippet?
#include<stdio.h>
main()
{
char c = 'A'+255;
printf("%c", c);
}
Answer : A
Explanation
A, the range of ASCII values for the ASCII characters is 0-255. Hence the addition operation circulates back to ‘A’
Q 8 - What is the output of the following code snippet?
#include<stdio.h>
main()
{
short unsigned int i = 0;
printf("%u\n", i--);
}
Answer : A
Explanation
0, with post decrement operator value of the variable will be considered as the expression’s value and later gets decremented.
Q 9 - What is the output of the below code snippet?
#include<stdio.h>
main()
{
unsigned x = 5, y=&x, *p = y+0;
printf("%u",*p);
}
Answer : D
Explanation
5, as p holds the address of x which is y+0
Q 10 - What is your comment on the below C statement?
signed int *p=(int*)malloc(sizeof(unsigned int));
C - Memory will be allocated but cannot hold an int value in the memory
Answer : D
Explanation
Option (d), as the size of int and unsigned is same, no problem in allocating memory.
Q 11 - What is the output of the following code snippet?
#include<stdio.h>
main()
{
int x = 5;
if(x==5)
{
if(x==5) break;
printf("Hello");
}
printf("Hi");
}
Answer : A
Explanation
compile error, keyword break can appear only within loop/switch statement.
Q 12 - What is the output of the following code snippet?
#include<stdio.h>
main()
{
int x = 5;
if(x=5)
{
if(x=5) break;
printf("Hello");
}
printf("Hi");
}
Answer : A
Explanation
compile error, keyword break can appear only within loop/switch statement.
Q 13 - What is the output of the following code snippet?
#include<stdio.h>
main()
{
int x = 5;
if(x=5)
{
if(x=5) printf("Hello");
}
printf("Hi");
}
Answer : A
Explanation
HelloHi, both the if statement’s expression evaluates to be true.
Q 14 - What is the output of the below code snippet?
#include<stdio.h>
main()
{
for(;;)printf("Hello");
}
Answer : A
Explanation
infinite loop, with second expression of ‘for’ being absent it is considered as true by default.
Q 15 - What is the output of the below code snippet?
#include<stdio.h>
main()
{
for()printf("Hello");
}
Answer : D
Explanation
Compiler error, semi colons need to appear though the expressions are optional for the ‘for’ loop.
Q 16 - What is the output of the below code snippet?
#include<stdio.h>
main()
{
for(1;2;3)
printf("Hello");
}
Answer : A
Explanation
infinite loop, as the second expression is non-0, hence the condition is always true.
Answer : D
Explanation
-2, the one’s compliment of 1 is 1110 (binary) which is equivalent to two’s compliment of 2, ie -2.
Q 18 - What is the output of the following program?
#include<stdio.h>
void f()
{
static int i;
++i;
printf("%d", i);
}
main()
{
f();
f();
f();
}
Answer : D
Explanation
1 2 3, A static local variables retains its value between the function calls and the default value is 0.
Q 19 - What is the output of the following code snippet?
#include<stdio.h>
main()
{
int *p = 15;
printf("%d",*p);
}
Answer : C
Explanation
Runtime error, as the pointer variable is not holding proper address, writing/reading the data from the same raises runtime error.
Q 20 - What is the output of the following program?
#include<stdio.h>
main()
{
register int x = 5;
int *p;
p=&x;
x++;
printf("%d",*p);
}
Answer : A
Explanation
Compile error, we cannot take the address of a register variable.
Q 21 - What is the output of the following program?
#include<stdio.h>
main()
{
int x = 65, *p = &x;
void *q=p;
char *r=q;
printf("%c",*r);
}
Answer : B
Explanation
A, void pointer is a generic pointer and can hold any variable’s address. ASCII character for the value 65 is ‘A’
Q 22 - What is the output of the following program?
#include<stdio.h>
void f()
{
printf(“Hello\n”);
}
main()
{
;
}
B - Error, as the function is not called.
C - Error, as the function is defined without its declaration
Answer : A
Explanation
No output, apart from the option (a) rest of the comments against the options are invalid.
Q 23 - What is the output of the following program?
#include<stdio.h>
main()
{
printf("\");
}
Answer : D
Explanation
Compile error, Format string of printf is not terminated.
Q 24 - What is the output of the following program?
#include<stdio.h>
{
int x = 1;
switch(x)
{
default: printf("Hello");
case 1: printf("hi"); break;
}
}
Answer : B
Explanation
Hi, control reaches default-case after comparing the rest of case constants.
Q 25 - What is the output of the following program?
#include<stdio.h>
main()
{
struct { int x;} var = {5}, *p = &var;
printf("%d %d %d",var.x,p->x,(*p).x);
}
Answer : A
Explanation
5 5 5, the two possible ways of accessing structure elements using pointer is by using -> (arrow operator) OR *.
Q 26 - What is the output of the following program?
#include<stdio.h>
void swap(int m, int n)
{
int x = m;
m = n;
n = x;
}
main()
{
int x=5, y=3;
swap(x,y);
printf("%d %d", x, y);
}
Answer : B
Explanation
5 3, call by value mechanism can’t alter actual arguments.
#include <stdio.h>
void swap(int m, int n)
{
int x = m;
m = n;
n = x;
}
main()
{
int x=5, y=3;
swap(x,y);
printf("%d %d", x, y);
}
Q 27 - What will be printed for the below statement?
#include<stdio.h>
main()
{
printf("%d",strcmp("strcmp()","strcmp()"));
}
Answer : A
Explanation
0, strcmp return 0 if both the strings are equal
Q 28 - What is the following program doing?
#include<stdio.h>
main()
{
FILE *stream=fopen("a.txt",'r');
}
A - Trying to open “a.txt” in read mode
B - Trying to open “a.txt” in write mode.
Answer : D
Explanation
Compile error, second argument for fopen is invalid, should be a string.
Q 29 - What is the output of the following program?
#include<stdio.h>
main()
{
int r, x = 2;
float y = 5;
r = y%x;
printf("%d", r);
}
Answer : D
Explanation
Compile Error, It is invalid that either of the operands for the modulus operator (%) is a real number.
Q 30 - Which operator is used to continue the definition of macro in the next line?
Answer : D
Explanation
\, the first two are stringize and token pasting operators respectively. There is no such operator called $.
Q 31 - What is the size of the following union definition?
#include<stdio.h>
union abc {
char a,b,c,d,e,f,g,h;
int i;
}abc;
main()
{
printf( "%d", sizeof( abc ));
}
Answer : C
Explanation
union size is biggest element size of it. All the elements of the union share common memory.
Answer : D
Explanation
The size of ‘int’ depends upon the complier i.e. whether it is a 16 bit or 32 bit.
Q 33 - The type name/reserved word ‘short’ is ___
Answer : D
Explanation
short is used as an alternative of short int.
Q 34 - What is the value of ‘y’ for the following code snippet?
#include<stdio.h>
main()
{
int x = 1;
float y = x>>2;
printf( "%f", y );
}
Answer : C
Explanation
0, data bits are lost for the above shift operation hence the value is 0.
Q 35 - What is the output of the following program?
#include<stdio.h>
main()
{
float t = 2;
switch(t)
{
case 2: printf("Hi");
default: printf("Hello");
}
}
Answer : D
Explanation
Error, switch expression can’t be float value.
Q 36 - 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 37 - What is the output of the following program?
#include<stdio.h>
main()
{
int i = 1;
while( i++<=5 )
printf("%d ",i++);
}
Answer : C
Explanation
2 4 6, at while first compared and later incremented and in printf printed first and incremented later.
Q 38 - What is the output of the following program?
#include<stdio.h>
main()
{
int i = 1;
while(i++<=5);
printf("%d ",i++);
}
Answer : B
Explanation
6, there is an empty statement following ‘while’.
Q 39 - What is the output of the following program?
#include<stdio.h>
main()
{
int x = 1;
do
printf("%d ", x);
while(x++<=1);
}
Answer : B
Explanation
1 2, do..while is an entry control loop. As the expression x++ is post form loop continues for 2nd time also.
Q 40 - What is the output of the following program?
#include<stdio.h>
main()
{
int a[] = {1,2}, *p = a;
printf("%d", p[1]);
}
Answer : B
Explanation
2, as ‘p’ holds the base address then we can access array using ‘p’ just like with ‘a’
Q 41 - What is the output of the following program?
#include<stdio.h>
main()
{
int a[3] = {2,1};
printf("%d", a[a[1]]);
}
Answer : B
Explanation
1, The inner indirection evaluates to 1, and the value at index 1 for outer indirection is 1.
Q 42 - What is the output of the following program?
#include<stdio.h>
main()
{
int a[3] = {2,,1};
printf("%d", a[a[0]]);
}
Answer : D
Explanation
Compile error, invalid syntax in initializing the array.
Q 43 - What is the output of the following program?
#include<stdio.h>
main()
{
int a[] = {2,1};
printf("%d", *a);
}
Answer : C
Explanation
2, as ‘a’ refers to base address.
Q 44 - What is the output of the following program?
#include<stdio.h>
main()
{
int i = 1;
Charminar:
printf("%d ",i++);
if(i==3) break;
if(i<=5) goto Charminar;
}
Answer : D
Explanation
Compile error, wrong place for ‘break’ to appear.
Q 45 - What is the output of the following program?
#include<stdio.h>
main()
{
int i = 13, j = 60;
i ^= j;
j ^= i;
i ^= j;
printf("%d %d", i, j);
}
Answer : B
Explanation
60 13, its swapping.
Q 46 - What is the output of the following program?
#include<stdio.h>
main()
{
union abc {
int x;
char ch;
}var;
var.ch = 'A';
printf("%d", var.x);
}
Answer : C
Explanation
65, as the union variables share common memory for all its elements, x gets ‘A’ whose ASCII value is 65 and is printed.
Answer : C
Explanation
x, there is no such mode called “x”.
Q 48 - Function fopen() with the mode "r+" tries to open the file for __
Answer : A
Explanation
Option (a), the file should exist and opens for both reading & writing.
Q 49 - Identify the invalid constant used in fseek() function as ‘whence’ reference.
Answer : C
Explanation
SEEK_BEG, all the rest are valid constants defined in ‘stdio.h’
Q 50 - First operating system designed using C programming language.
Answer : C
Explanation
UNIX. C actually invented to write an operation system called UNIX. By 1973 the entire UNIX OS is designed using C.
Answer Sheet
| Question Number | Answer Key |
|---|---|
| 1 | D |
| 2 | D |
| 3 | C |
| 4 | A |
| 5 | A |
| 6 | C |
| 7 | A |
| 8 | A |
| 9 | D |
| 10 | D |
| 11 | A |
| 12 | A |
| 13 | A |
| 14 | A |
| 15 | D |
| 16 | A |
| 17 | D |
| 18 | D |
| 19 | C |
| 20 | A |
| 21 | B |
| 22 | A |
| 23 | D |
| 24 | B |
| 25 | A |
| 26 | B |
| 27 | A |
| 28 | D |
| 29 | D |
| 30 | D |
| 31 | C |
| 32 | D |
| 33 | D |
| 34 | C |
| 35 | D |
| 36 | B |
| 37 | C |
| 38 | B |
| 39 | B |
| 40 | B |
| 41 | B |
| 42 | D |
| 43 | C |
| 44 | D |
| 45 | B |
| 46 | C |
| 47 | C |
| 48 | A |
| 49 | C |
| 50 | C |