C Programming Mock Test


Advertisements


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.

Questions and Answers

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); 
} 

A - 5

B - 6

C - Runtime error

D - Compile error

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); 
}

A - 5

B - 6

C - Runtime error

D - Compile error

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");
	}
}

A - Equal strings

B - Unequal strings

C - No output

D - Compilation error

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);
}

A - a=5, b=3

B - a=5, b=3, c=0

C - a=5, b=3, 0

D - compile error

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);
}

A - 2.30

B - 2.3

C - Compile error

D - 2.0

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);
}

A - 0 1.

B - 0 2

C - 0 8

D - Compile error

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);
}

A - A

B - B

C - Overflow error at runtime

D - Compile error

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--);
}

A - 0

B - Compile error

C - 65535

D - 32767

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);
}

A - Address of x

B - Address of y

C - Address of p

D - 5

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));

A - Improper type casting

B - Would throw Runtime error

C - Memory will be allocated but cannot hold an int value in the memory

D - No issue with statement

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");
}

A - Compile error

B - Hi

C - HelloHi

D - Hello

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");
}

A - Compile error

B - Hi

C - HelloHi

D - Compiler warning

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");
}

A - HelloHi

B - Hi

C - Hello

D - Compiler error

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");
}

A - Infinite loop

B - Prints “Hello” once.

C - No output

D - Compile error

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");
}

A - Infinite loop

B - Prints “Hello” once.

C - No output

D - Compile error

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");
}

A - Infinite loop

B - Prints “Hello” once.

C - No output

D - Compile error

Answer : A

Explanation

infinite loop, as the second expression is non-0, hence the condition is always true.

Q 17 - int x=~1; What is the value of 'x'?

A - 1

B - -1

C - 2

D - -2

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(); 
}

A - 1 1 1

B - 0 0 0

C - 3 2 1

D - 1 2 3

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);
}

A - 15

B - Garbage value

C - Runtime error

D - Compiler error

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);
}

A - Compile error

B - 5

C - 6

D - Garbage value

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);
}

A - Garbage character.

B - A

C - 65

D - Compile error

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() 
{
 ;
}

A - No output

B - Error, as the function is not called.

C - Error, as the function is defined without its declaration

D -Error, as the main() function is left empty

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("\");
}

A - \

B - \"

C - "

D - Compile error

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;
   }
}

A - Hello

B - Hi

C - HelloHi

D - Compile error

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); 
}

A - 5 5 5

B - 5 5 garbage value

C - 5 5 0

D - Compile error

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);
}

A - 3 5

B - 5 3

C - 5 5

D - Compile error

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()"));
}

A - 0

B - 1

C - -1

D - Invalid use of strcmp() function

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.

C - “stream” is an invalid identifier

D - Compile error

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); 
}

A - 1

B - 0

C - 2

D - Compile error

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?

A - #

B - ##

C - $

D - \

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 ));
}

A - 1

B - 2

C - 4

D - 8

Answer : C

Explanation

union size is biggest element size of it. All the elements of the union share common memory.

Q 32 - What is the size of ‘int’?

A - 2

B - 4

C - 8

D - Compiler dependent

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 ___

A - short long

B - short char

C - short float

D - short int

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 );
}

A - 4

B - 0.5

C - 0

D - 1

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");
   }
}

A - Hi

B - HiHello

C - Hello

D - Error

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++);
}

A - 1 3 5

B - 2 4

C - 2 4 6

D - 2

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++);
}

A - 1 3 5

B - 2 4

C - 2 4 6

D - 2

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++);
}

A - 4

B - 6

C - 2 6

D - 2 4

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);
}

A - 1

B - 1 2

C - No output

D - Compile error

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]); 
}

A - 1

B - 2

C - Compile error

D - Runtime error

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]]); 
}

A - 0

B - 1

C - 2

D - 3

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]]); 
}

A - 0

B - 1

C - 2

D - Compile error

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); 
}

A - 0

B - 1

C - 2

D - Compile error.

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;
}

A - 1 2

B - 1 2 3

C - 1 2 4 5

D - Compile error

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);
}

A - 73 73

B - 60 13

C - 13 60

D - 60 60

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);
}

A - A

B - Garbage value

C - 65

D - 97

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.

Q 47 - Identify the incorrect file opening mode from the following.

A - r

B - w

C - x

D - a

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 __

A - reading and writing

B - reading and adding new content

C - only for reading

D - it works only for directories

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.

A - SEEK_SET

B - SEEK_CUR

C - SEEK_BEG

D - SEEK_END

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.

A - DOS

B - Windows

C - UNIX

D - Mac

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

cprogramming_questions_answers.htm

Advertisements
E-Books Store