C LANGUAGE QUESTIONS WITH SOLUTION

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C language objective types questions and answers with solution or explanation

1.

#include<stdio.h>
int main(){
    int a=0;
    #if (a==0)
         printf("Equal");
    #else if
         printf("Not equal");
    #endif
    return 0;
}

(A) Equal
(B) Not equal
(C) Null
(D) Garbage
(E) Compilation error

Explanation:

Syntax of conditional preprocessor directive (if) is:

#if <Constant expression>
#else
#endif

In this code (a==0) is not constant expression. A constant expression mean expression doesn’t contain any variables.
Note: const int a; Here a is also variable     

2.

What will be output if you will execute following c code?

#include<stdio.h>
int main(){
    for(;NULL;)
         printf("cquestionbank");
    return 0;
}

(A) c
(B) bank
(C) cquestionbank
(D) Infinite loop
(E) Compilation error

Explanation:

Here NULL is micro constantan. Value of this symbolic constant is 0 or 0L as defined stdio.h:

#ifndef NULL
#  if defined(__TINY__) || defined(__SMALL__) || defined(__MEDIUM__)
#      define NULL    0
#  else
#      define NULL    0L
#  endif
#endif

So corresponding intermediate file of above code will be:


int main(){
    for(;0;)
    printf("cquestionbank");
    return 0;
}

As you know in c :
0: Means false
Non- zero: True

So for loop should not execute any time because intitial condtion is false. But it is bug of turbo c compiler. Loop will execute one time and it will print : cquestionbank

3.

What will be output if you will execute following c code?

#include<stdio.h>
int main(){
    int x=25;
    if(!!x)
         printf("%d",!x);
    else
         printf("%d",x);
    return 0;
}

(A) 0
(B) 25
(C) 1
(D) -1
(E) 2
Explanation:

! is negation operator.
!x = 0 if x is non-zero number.
!x = 1 if x is equal to zero.
So,
!!x
=! (! x)
=! (! 25)
=! (0)
=1
As we know in c:
Zero: It represents false.
Non-zero: It represents false.
if (1) means condition is true hence if part will execute.
!x =! 1 = 0
Hence printf statement will print zero in the console window.

4.

What will be output if you will execute following c code?

#include<stdio.h>
int main(){
    float a=0.5, b=0.9;
    if(a&&b>0.9)
         printf("Sachin");
    else
         printf("Rahul");
    return 0;
}

(A) Sachin
(B) Rahul
(C) null
(D) Run time error
(E) Compilation error

Explanation:

Consider on the expression:
a && b > 0.9
As we know > operator enjoy higher precedence than && operator.
So expression will be
a && (b > 0.9)
=0.5 && (0.9 > 0.9)
Properties of > (Greater than operator)
a > b returns 1 if a is greater than b.
a > b return 0 if a is less than or equal to b.
So our expression became:
= 0.5 && 0
In c zero represents false and non-zero represents true.
= true && false
= false
= 0
So, if (0) means condition is false. Hence else part will execute.

5.

What will be output if you will execute following c code?

#include<stdio.h>
int main(){
    int x=5, y=10;
    if(!(!x) && x)
         printf("%d",x);
    else
         printf("%d",y);
    return 0 ;
}

(A) 1
(B) 0
(C)
5
(D) 10
(E) Compilation error

Explanation:

Consider on expression:
! (! x) && x
=! (! 5) && 5
=! 0 && 5
=1 && 5
=1
So, if condition is true.

6.

What will be output if you will execute following c code?

#include<stdio.h>
int main(){
    char ch=321;
    printf("%d %c",ch,ch);
    return 0 ;
}

(A) 321 #
(B) 65 A
(C) 321 !
(D) 66 B
(E) Compilation error

Explanation:

Number 321 is beyond the range of char variable ch. So ch will store corresponding cyclic value as shown in the figure:


Equivalent cyclic value of 321 = 321 % 128 = 65
65 is ASCII value of character 'A'

7.

What will be output if you will execute following c code?

#include<stdio.h>
int main(){
int a,b;
    a = -3- -3;
    b = -3 - - (-3 );
    printf("%d %d",a,b);
    return 0 ;
}

(A) 0 0
(B) 0 -3
(C) -3 0
(D) 0 -6
(E) Compilation error

Explanation:

- Operator in c has two forms:
- : Unary minus operator (It requires one operand)
- : Binary minus operator (It requires two operands)
Note: Unary minus operator has higher precedence than binary minus operator.

8.

What will be output if you will execute following c code?

#include<stdio.h>
int main(){
    int x;
    x= -2 + 11 - 7 * 9 % 6 / 12;
    printf("%d",x);
    return 0 ;
}

(A) 6
(B) 7
(C) 8
(D) 9
(E) Compilation error

Explanation:

Consider on the expression
x = -2 + 11 - 7 * 9 % 6 / 12
There are seven different type of operator in the above expression:



Operator
Precedence
Associative
-
1
Right to left
* , % , /
2
Left to right
- , +
3
Left to right
=
4
Right to left

First of all unary minus will perform the operation
 x = (-2) + 11 - 7 * 9 % 6 / 12
 Now multiplication operator will perform the operation
 x = (-2) + 11 - (7 * 9) % 6 / 12
 x = (-2) + 11 - 63 % 6 / 12
 After this modular division operator will perform operation:
 x = (-2) + 11 - (63 % 6) / 12
 x = (-2) + 11 - 3  / 12
 After this division will perform the operation:
 x = (-2) + 11 - (3 / 12)
 x = (-2) + 11 - 0
 Now binary plus operator will perform the operation:
 x = ((-2) + 11) - 0
 x = 9 - 0
 Now binary minus operator will perform the operation:
 x = 9
 At the end assignment operator will perform the operation and it will assign 9 to variable x.

9.

What will be output if you will execute following c code?

#include<stdio.h>
int main(){
    int x=3, y=4, z=4;
    printf("%d", (z>=y>=x?100:200));
   
    return 0 ;
}

(A) 100
(B) 200
(C) 0
(D) 1
(E) Compilation error

Explanation:

Consider on arithmetical expression:
z>=y>=x? 100:200
= (z >= y >= x? 100: 200)
= (4 >= 4 >= 3? 100: 200)
= ((4 >= 4) >= 3? 100: 200)
= (1 >= 3? 100: 200)
= (0? 100: 200)
= 200

10.

What will be output if you will execute following c code?

#include<stdio.h>
int main(){
    int a=30, b=40, x;
    x=(a!=10) && (b=50);
    printf("%d",x);
    return 0 ;
}

(A) 1
(B)
2
(C)
3
(D) 4
(E) Compilation error

Explanation:

(a!= 10) && (b = 50)
= (30! = 10) && (50)
= 1 && 50
= 1

11.

What will be output if you will execute following c code?

#include<stdio.h>
int main(){
    float x=12.25, y=13.65;
    if(x=y)
         printf("x and y are equal");
    else
         printf("x and y are not equal");
    return 0 ;
}

(A) x and y are equal
(B) x and y are not equal
(C) It will print nothing
(D) Run time error
(E) Compilation error

Explanation:

= is assignment operator.
So, x=y value of variable y will assign to variable x.
    x= 13.65
As we know in c:
Zero represents false.
Any non-zero number represents true.
Hence if (13.65) is true condition.

12.

What will be output if you will execute following c code?

#include<stdio.h>
int main(){
    int i=1, j=1;
    for(;j;printf("%d%d\t",i,j))
         j=i++ <= 5;
    return 0 ;
}
(A) 1 2 3 4 5
(B) 11 12 13 14
(C)
21 31 41 51 61 70
(D) Infinite loop
(E) Compilation error

Explanation:

Syntax of for loop is:

for (exp1;exp2;exp3){
    <Statements>
}
Note: all Exp1, Exp2, Exp3 and <statements> are optional.
Order of evaluation is:
In first cycle
1. Exp1
2. Exp2
3. <Statement>
4. Exp2
In rest cycles
1. Exp2
2. <Statements>
3. Exp3
Now we come to our question.
In first cycle
1. It has not exp1
2. Exp2 is j which is equal to 1 i.e. condition is true
3. <Statements> is j=i++ <= 5
j = 1 <= 5
j = 1
i = 2 (Due to postfix increment operator)
4. Exp3 is printf statement which will print i as 2 and j as 1

In second cycle
1. Exp2 is j which is equal to 1 i.e. condition is true
2. <Statements> is j=i++ <= 5
j = 2 <= 5
j = 1
i = 3 (Due to postfix increment operator)
3. Exp3 is printf statement which will print i as 3 and j as 1

In third cycle
1. Exp2 is j which is equal to 1 i.e. condition is true
2. <Statements> is j=i++ <= 5
j = 3 <= 5
j = 1
i = 4 (Due to postfix increment operator)
3. Exp3 is printf statement which will print i as 4 and j as 1

In fourth cycle
1. Exp2 is j which is equal to 1 i.e. condition is true
2. <Statements> is j=i++ <= 5
j = 4 <= 5
j = 1
i = 5 (Due to postfix increment operator)
3. Exp3 is printf statement which will print i as 4 and j as 1

In fifth cycle
1. Exp2 is j which is equal to 1 i.e. condition is true
2. <Statements> is j=i++ <= 5
j = 5 <= 5
j = 1
i = 6 (Due to postfix increment operator)
3. Exp3 is printf statement which will print i as 6 and j as 1

In sixth cycle
1. Exp2 is j which is equal to 1 i.e. condition is true
2. <Statements> is j=i++ <= 5
j = 6 <= 5
j = 0
i = 7 (Due to postfix increment operator)
3. Exp3 is printf statement which will print i as 7 and j as 0

In seventh cycle
1. Exp2 is j which is equal to 0 i.e. condition is false. So loop will terminate.

13.

What function is used to release the allocated memory space?

(A) deallocate()
(B) release ()
(C) free ()
(D) drop()
(E) empty ()

Explanation:
**

14.

What will be output if you will execute following c code?

#include<stdio.h>
auto int a=5;
int main(){
    int x;
    x=~a+a&a+a<<a;
    printf("%d",x);
    return 0;
}


(A)
0
(B) 1
(C) 154
(D) 155
(E) Compilation error

Explanation:
**

15.

What will be output if you will execute following c code?

#include<stdio.h>
void main(){
    int a=5;
    {
         int b=10;
         ++b;
         ++a;
         {
             int a=20;
             ++a;
             a=++b;
         }
         ++a;
         ++b;
         printf("%d %d",a,b);
    }
    printf(" %d",a);
}

(A) 7 13 7
(B) 13 13 13
(C) 13 13 5
(D)
6  13 5
(E) Compilation error

Explanation:
**

16.

What will be output if you will execute following c code?

#include<stdio.h>
#include<conio.h>
void main(){
    int a[]={0,1,2,3,4,5,6,7,8,9,10};
    int i=0,num;
    num=a[++i+a[++i]]+a[++i];
    printf("%d",num);
}

(A) 6
(B) 7
(C) 8
(D) 9
(E) Compilation error

Explanation:

a[++i+a[++i]]+a[++i]

As we know in any expression pre increment operator first increment the value of variable  then final value assign to all variable.
Variable i has incremented three times so final value of I will be 3. Now 3 will be assigned to all i. So expression will be:
= a [3+a [3] +a [3]
= a [3 + 3] + 3
=a [6] + 3
= 6 + 3
=9

17.

What will be output if you will execute following c code?

#include<stdio.h>
#include<conio.h>
void main(){
    int i=3,val;
    val=sizeof f(i)+ +f(i=1)+ +f(i-1);
    printf("%d %d",val,i);
}
int f(int num){
    return num*5;
}

(A) 2 0
(B) 7 1
(C) 17 0
(D)
2 1
(E) Compilation error

Explanation:

Consider on the expression:
sizeof f(i)+ +f(i=1)+ +f(i-1)  //i=3
= sizeof f(3)+ +f(i=1)+ +f(i-1)
= sizeof 15 + +f(i=1)+ +f(i-1) 
= 2 + +f(i=1)+ +f(i-1)
= 2 + f(1) +  +f(0)  //i=1
= 2 + 5 + f(0)
= 7 + 0
= 7

18.

What will be output if you will execute following c code?

#include<stdio.h>
#include<conio.h>
void main(){
    int i;
    (i=8)+=1;
    printf("%d",i);
}

(A) 9
(B) 10
(C) 32
(D) 34
(E) Compilation error

Explanation:
**

19.

What will be output if you will execute following c code?

#include<stdio.h>
#include<conio.h>
void main(){
    char c=-'a';
    printf("%d",c);
}

(A) 65
(B) -65
(C)
-a
(D) -97
(E) Compilation error

Explanation:

ASCII value of character ‘a’ is 97.

20.

What will be output if you will execute following c code?

#include<stdio.h>
int main(){
    int num,a=5;
    num=-a--;
    printf("%d  %d",num,a);
}

(A) 5  4
(B) -4 4
(C) -5 4
(D) -4 5
(E) Compilation error

Explanation:

Post decrement operator first assign the value then it decrements the value. 
num = -a—-
num = -5
Now value of variable a will be 4.

94 comments:

  1. Excellent work, Mr. Blogger. I am a fresher student. I am trying to understand C language. This post is MOST HELPFUL..!!!

    God bless you. Please keep up the good work

    ReplyDelete

  2. Write a program in C to delete all chars in a Text file before encountering word "WORD". after encountering word "WORD, copy 2 to 100 long long ints from file seperated by commas until you get word "/WORD"

    Adam

    ReplyDelete

  3. now i m very happy..it is useful to improve my c laguage skills... i can feel very happy to solve these questions.... thank u
    sanjapu shiva

    ReplyDelete

  4. where r the damn answers..
    how would we telly our answers...

    ReplyDelete

  5. great job!!
    really good questions! these really helped to clear up my concepts!
    Thanks!

    ReplyDelete

  6. how the answer of question number 19 is 10?
    Please Explain.

    ReplyDelete

  7. where are the answers given.can u explain answers of qno 23 and 39.?

    ReplyDelete

  8. nice questions,but did not know how to fuck u?

    ReplyDelete

  9. thank you sir, iam shashank tomar mca student,you are giving good questions.

    ReplyDelete

  10. sir these problems are very good . everyone can understand about c LAn through it.

    ReplyDelete

  11. but their is no programs like to see reverse programs etc so plz also add sum prgrm like dnt ask vch one is correct out put

    ReplyDelete

  12. where is answer?????????????

    ReplyDelete

  13. very easy questions .include pointers and linked lists.then may b cmplcatd

    ReplyDelete

  14. where r answers?

    ReplyDelete

  15. no use without answers!!!!!!!!!!!!

    ReplyDelete

  16. no use without answers!!!!!!!!!!!!

    ReplyDelete

  17. u r correct re.....no use without answers!!!!!

    ReplyDelete

  18. dam it this are easy ones, u can give bit complicated, if u add pointers and linked lists it will be useful

    ReplyDelete
  19. Anamika chhabra5/24/10, 2:24 PM

    answer of 16th ques would be 6 , not 9...

    ReplyDelete

  20. i am very happy you improve my c laguage skills... i can feel very happy to solve these questions.... thank u

    ReplyDelete

  21. Hi Anamika,
    I checked answer again. Answer of question 16. is correct. Please check the explanation

    ReplyDelete

  22. very good bosss

    ReplyDelete

  23. give the ans of 18 q

    ReplyDelete

  24. thanks...
    it revised me all things that i have read in the start of semester...
    and hopefully it will help me in my terminal!

    ReplyDelete

  25. hi sir
    these questions are very good and helpful in understanding C
    ur explanation way is great

    ReplyDelete
  26. sunil kumar verma6/4/10, 10:58 PM

    thanks sir
    i m very happy to see this problem.

    ReplyDelete

  27. Hi sir...
    Really its a awesome explanation about this C language...

    ReplyDelete

  28. good job bro....can u think abt that...

    printf("%d", (z>=y>=x?100:200));

    if the z>=y>=x is true than it print outs 100 not 200

    ReplyDelete

  29. Hi Aman verma,
    Yes if z>=y>=x is true then it will print 100.But in questions 9, it is not true. Please look the explanation carefully.
    Hints: Read about return type of conditional operators,precedence and associate of operators.

    ReplyDelete

  30. thanx a lot i was searching on net in no.s of site but no one was better then this

    ReplyDelete

  31. 18 is not correct.. its actually "Lvalue required error" Compilation error

    ReplyDelete

  33. hi all q r good

    ReplyDelete

  34. Thank u so much..
    this s very useful to me..

    ReplyDelete

  35. Thnxxxxx
    These ques r very good and hardddd,.....

    ReplyDelete

  36. Good Questions!!!!!!
    You cleared my fundamentals
    Thanks alot
    Its good for a beginner

    ReplyDelete

  37. Request: Please provide the explanation of 14 & 15 questions.

    Thanks

    ReplyDelete

  38. good question......

    ReplyDelete

  39. how the key-word in c language

    ReplyDelete

  40. good work boss.
    i enjoyed the questions :)

    -Rahil

    ReplyDelete

  41. work done is good...
    but there are some mistakes in answers...
    question collection reflects some good concepts...

    ReplyDelete

  42. hi.....
    nice Q...but some Qustion are vry difficult/

    ReplyDelete

  43. really great-:)

    ReplyDelete

  44. Thanks dear, this blog is good to clear many concept.

    ReplyDelete

  45. this are really good cleard my concept

    ReplyDelete

  46. i want to mora and more Question
    ya to baccho wala khal tha.............
    plz give high level Question sirrrrrrrrrrrrrrr

    ReplyDelete

  47. Superb one's No words seriously

    ReplyDelete

  48. these questions are very good and helpful in understanding C
    ur explanation way is great

    ReplyDelete

  49. great job
    keep it up

    ReplyDelete

  50. ya its very useful to me to improve my skills in c...
    any way thanks for ur work blogger

    ReplyDelete

  51. good work..

    ReplyDelete

  52. importance of return type in main function

    ReplyDelete

  53. very very very usefull this type of obj qns in interview
    thanks anamika

    ReplyDelete

  54. thanks you are doing very good work for the student it is very helpful to every student.

    ReplyDelete

  55. its really a nice one which developes our skill in c programming......
    so i am always grateful to u

    ReplyDelete

  56. Thanks a lot! I enjoyed doing it!

    ReplyDelete

  57. Some of the questions have answers, but it won't compile in a gcc compiler. You should consider that!

    ReplyDelete

  58. you are very interesting one.i like you ,sir.

    ReplyDelete

  59. thanks.....

    ReplyDelete

  60. thank you very much ,you have done very good job,
    blessings in tons, may god bless you.

    if you have any doubt or query
    please contact me at geniushkg@gmail.com

    ReplyDelete

  61. This comment has been removed by the author.

    ReplyDelete

  62. 17 th is not clear plzzzzzzz explain......

    ReplyDelete

  63. SIR KEEP IT UP THAT'S THE NICE WAY TO BUILT KNOWLEDGE OF A PROGRAMMER.

    AARAV

    ReplyDelete

  64. Good post but you need much care for answers

    ReplyDelete
  65. rathod sanjay4/21/11, 12:00 AM

    I improve best programming knowledge using this quiz....

    ReplyDelete

  68. correct ra 16 que ans is 6

    ReplyDelete

  69. Here we can find multiple choice, this is great way and you are given to this information to us, help of this e book we study and gain some knowledge.

    ReplyDelete

  70. ans. of 18th question is wrong.it would be E option.

    ReplyDelete

  71. hey its to good,thx a lot

    ReplyDelete

  72. AWESOME WORK DUDE......bless you!!

    ReplyDelete

  73. how to make a quiz programme in c language ?

    ReplyDelete

  74. VERY GOOD QUESTION AND ANSWER BUT I NEED MORE TRICKY QUESTION. PLZZZZZZZZZZZZZZZZZZ

    ReplyDelete
  75. vasanthakumar7/16/11, 2:03 PM

    good work.

    ReplyDelete

  78. i=0;
    i= i++ + ++i + i++ + i;

    output=?

    ReplyDelete

  79. A very good work u r doing.Thanks .............
    plz. post more on pointers

    ReplyDelete

  80. pleas post more question

    ReplyDelete

  81. #include
    #include
    void main(){
    int i;
    (i=8)+=1;
    printf("%d",i);
    }


    In your answers its showing 34. But I executed this and got output 9..

    ReplyDelete

  82. dear dasu answer is correct 9

    ReplyDelete

  83. thanks...........my improve c....so thanks very good question

    ReplyDelete

  84. # include
    main()
    {
    int a ;
    if(a = 0)
    printf("true");
    else
    printf("false");
    }

    output: true.

    why the output is true when the value of a is 0

    ReplyDelete

  85. you should write if(a==0)
    a=0 means 0 is assigning to variable a and in c 0 means false and any non-zero values means true

    ReplyDelete

  86. Can I know the answer to:
    Write a program that reads a list of integers from the keyboard and creates the following information:
    a.)Finds and prints the sum and the average of the integers.
    b.)Find and prints the smallest integer.
    c.)Prints a Boolean(true or false) if some of them are less than 20.
    d.)Prints a Boolean (true or false) if all of them are between 10 and 90.
    Please help me out to solve this Problem :)

    ReplyDelete

  87. #include
    #include
    void main(){
    int a[]={0,1,2,3,4,5,6,7,8,9,10};
    int i=0,num;
    num=a[++i+a[++i]]+a[++i];
    printf("%d",num);
    }



    why its ans is 9 i didn't get it

    ReplyDelete

  88. must say a good work indeed...
    your qs have really made me feel more comfortable....
    thanks!!

    ReplyDelete

  89. sir in question number 17 f shoul have a prototype ......



    in question 18 the answer will be 9 not 34

    ReplyDelete

  90. what the hell? in question 3, the ELSE part is executed which prints out the value of x. the value of x is still 25 and is unchanged by operator used inside the condition to be verified in the IF statement.

    ReplyDelete

  91. hi sir i am rohit you are giving good questions .thank
    s for this.....

    ReplyDelete

  92. these questions as well as answers are very much useful to freshers... thank u...keep posting further..

    ReplyDelete

  93. your explanation are very well. nice work done

    ReplyDelete

  94. Superb material

    i have a doubt .

    in an expression , operation will be left to right or right to left ?

    ReplyDelete

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